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Acharya N G Ranga Agricultural University, Guntur

The Andhra Pradesh Agricultural University (APAU) was established on 12th June 1964 at Hyderabad. The University was formally inaugurated on 20th March 1965 by Late Shri. Lal Bahadur Shastri, the then Hon`ble Prime Minister of India. Another significant milestone was the inauguration of the building programme of the university by Late Smt. Indira Gandhi,the then Hon`ble Prime Minister of India on 23rd June 1966. The University was renamed as Acharya N. G. Ranga Agricultural University on 7th November 1996 in honour and memory of an outstanding parliamentarian Acharya Nayukulu Gogineni Ranga, who rendered remarkable selfless service for the cause of farmers and is regarded as an outstanding educationist, kisan leader and freedom fighter. HISTORICAL MILESTONE Acharya N. G. Ranga Agricultural University (ANGRAU) was established under the name of Andhra Pradesh Agricultural University (APAU) on the 12th of June 1964 through the APAU Act 1963. Later, it was renamed as Acharya N. G. Ranga Agricultural University on the 7th of November, 1996 in honour and memory of the noted Parliamentarian and Kisan Leader, Acharya N. G. Ranga. At the verge of completion of Golden Jubilee Year of the ANGRAU, it has given birth to a new State Agricultural University namely Prof. Jayashankar Telangana State Agricultural University with the bifurcation of the state of Andhra Pradesh as per the Andhra Pradesh Reorganization Act 2014. The ANGRAU at LAM, Guntur is serving the students and the farmers of 13 districts of new State of Andhra Pradesh with renewed interest and dedication. Genesis of ANGRAU in service of the farmers 1926: The Royal Commission emphasized the need for a strong research base for agricultural development in the country... 1949: The Radhakrishnan Commission (1949) on University Education led to the establishment of Rural Universities for the overall development of agriculture and rural life in the country... 1955: First Joint Indo-American Team studied the status and future needs of agricultural education in the country... 1960: Second Joint Indo-American Team (1960) headed by Dr. M. S. Randhawa, the then Vice-President of Indian Council of Agricultural Research recommended specifically the establishment of Farm Universities and spelt out the basic objectives of these Universities as Institutional Autonomy, inclusion of Agriculture, Veterinary / Animal Husbandry and Home Science, Integration of Teaching, Research and Extension... 1963: The Andhra Pradesh Agricultural University (APAU) Act enacted... June 12th 1964: Andhra Pradesh Agricultural University (APAU) was established at Hyderabad with Shri. O. Pulla Reddi, I.C.S. (Retired) was the first founder Vice-Chancellor of the University... June 1964: Re-affilitation of Colleges of Agriculture and Veterinary Science, Hyderabad (estt. in 1961, affiliated to Osmania University), Agricultural College, Bapatla (estt. in 1945, affiliated to Andhra University), Sri Venkateswara Agricultural College, Tirupati and Andhra Veterinary College, Tirupati (estt. in 1961, affiliated to Sri Venkateswara University)... 20th March 1965: Formal inauguration of APAU by Late Shri. Lal Bahadur Shastri, the then Hon`ble Prime Minister of India... 1964-66: The report of the Second National Education Commission headed by Dr. D.S. Kothari, Chairman of the University Grants Commission stressed the need for establishing at least one Agricultural University in each Indian State... 23, June 1966: Inauguration of the Administrative building of the university by Late Smt. Indira Gandhi, the then Hon`ble Prime Minister of India... July, 1966: Transfer of 41 Agricultural Research Stations, functioning under the Department of Agriculture... May, 1967: Transfer of Four Research Stations of the Animal Husbandry Department... 7th November 1996: Renaming of University as Acharya N. G. Ranga Agricultural University in honour and memory of an outstanding parliamentarian Acharya Nayukulu Gogineni Ranga... 15th July 2005: Establishment of Sri Venkateswara Veterinary University (SVVU) bifurcating ANGRAU by Act 18 of 2005... 26th June 2007: Establishment of Andhra Pradesh Horticultural University (APHU) bifurcating ANGRAU by the Act 30 of 2007... 2nd June 2014 As per the Andhra Pradesh Reorganization Act 2014, ANGRAU is now... serving the students and the farmers of 13 districts of new State of Andhra Pradesh with renewed interest and dedication...

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Subject: Genetics and Plant Breeding × End date: 2022 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    STABILITY ANALYSIS IN SORGHUM [Sorghum bicolor (L.) Moench] GENOTYPES
    (guntur, 2022-08-17) KAVYA, PATI; SATYANARAYANA RAO, V.
    The present investigation was carried out at Agricultural College farm, Bapatla, Andhra Pradesh with the following objectives: Study of variability, diversity, correlation and path analysis, combining ability, stability analysis and generation mean analysis for 13 quantitative characters The data was recorded on Days to 50% flowering (Days), Days to maturity (Days), Plant height (cm), Number of nodes per plant, Stem girth (cm), Panicle weight (g), 1000 grain weight (g), Fresh stalk yield (T ha-1), Juice yield (l ha-1), Brix per cent, Total soluble sugars ( % ), Ethanol yield (l ha-1), Grain yield (T ha-1). The analysis of variance indicated significant differences among the 110 genotypes indicating the existence of variability among the genotypes. Estimates of PCV were narrowly higher than the corresponding GCV values for the characters days to 50 % flowering, days to maturity and stem girth, while number of nodes per plant, fresh stalk yield (t/ha), grain yield (t/ha), brix %, T.S.S, juice yield (t/ha), ethanol yield (t/ha) showed moderate differences between PCV and GCV. Characters plant height (cm), 1000 grain weight, Panicle weight (gm) showed high magnitude of difference. Narrow and moderate difference between PCV and GCV indicating less environment influence on these characters. Therefore, selection based on phenotypic performance could be worth in achieving desired results. High heritability coupled with high genetic advance as percent of mean was observed for all the 13 characters studied. The diversity study for 110 genotypes were grouped into 8 clusters indicating the presence of a wide range of genetic diversity. Cluster- I, was possessing the highest number of genotypes i.e., 78 indicating the genetic similarity among them followed by Cluster- III with 15 genotypes, Cluster - II with 12 genotypes. Cluster - IV, V, VI, VII, VIII were monogenotypic indicating the uniqueness of the genotypes included in those clusters when compared to other genotypes included in the study. The cluster means for brix %, juice yield, ethanol yield and days to 50 % flowering were considered as criteria and for crossing, diverse parents were selected from various clusters. i.e., from cluster IV, cluster V, cluster VI, cluster VII, and cluster VIII for hybridization programme. xvii The correlation results in 110 genotypes for 13 characters revealed that ethanol yield has significant positive correlation with brix percent, total soluble sugars, juice yield while negative association with grain yield, plant height, days to 50% flowering and days to maturity. Path coefficient analysis revealed that juice yield exerted the highest positive direct effect on ethanol yield followed by brix %, total sugar yield along with positive correlation for all the above mentioned characters. Four lines were crossed with 4 testers selected from the divergence studies in L x T fashion. The pooled analysis of variance for 13 characters measured over three locations in the present investigation revealed significant differences among environments, lines, testers, crosses, environment x line x tester for all the characters studied except panicle weight. In the line x tester analysis, sca variance component estimates were greater than that of gca for the characters no of nodes, fresh stalk yield (t/ha),stem girth (cm), 1000 grain weight (g), panicle weight(g), brix%, total soluble sugars, juice yield(l/ha) and grain yield(t/ha) indicating the non-additive control of genetic variation in these traits. Female line 1 (ICSA-14029) was found to be promising general combiner for fresh stalk yield, brix%, total soluble sugars, juice yield, and ethanol yield with higher positive significant GCA effects, while line 4 (ICSA-14035) was negative significant for all the characters studied except stem girth and plant height indicating this line was poor combiner for all the characters. Among the testers which are used as male parents, tester 3 (ICSV 15006) has shown positive significant gca for all the traits like number of nodes, plant height, fresh stalk weight, stem girth, panicle weight, brix per cent, total soluble sugars, juice yield, ethanol yield followed by tester 2 (GGUB 28) possessing positive gca for juice yield and ethanol yield and tester 4 (IS 29308) had positive significant gca for brix %, total soluble sugars. Tester 1 (SEVS-08) recorded negative significant association for brix, total soluble solids, juice yield, ethanol yield and grain yield. Among the hybrids, hybrid ICSA 14029 x ICSV 15006 has excelled with high sca effects for brix%, total soluble sugars, juice yield and ethanol yield followed by hybrid ICSA 14029 x GGUB 28 having high sca effects for brix %, total soluble sugars, juice yield and ethanol yield, 1000 grain weight, panicle weight. Hybrid ICSA 14030 x IS 29308 showed high sca effects for brix, total soluble sugars, juice yield, ethanol yield, days to maturity, 1000 grain weight, panicle weight and negative significant for no. of nodes, days to 50 % flowering, fresh stalk yield, stem girth. Hybrid ICSA 14033 x SEVS-08 was possessing high sca effects for brix, total soluble sugars, juice yield and ethanol yield,1000 grain weight, days to 50% flowering and Number of nodes and negative effects for days to maturity, fresh stalk yield, stem girth and hybrid ICSA 14035 x SEVS-08 showing significant sca effects for juice and ethanol yield respectively. Among the Hybrids H-3, H-2, H-8 and H-10 were found to be superior for juice, brix percent and ethanol content. Hence the following hybrids can be used for further improvement. The range of heterosis over mid parent, better parent and commercial check indicated that it was high with respect to ethanol productivity related traits particularly juice yield and brix per cent. Considering standard heterosis as reference point for viz; xviii juice yield, brix and ethanol yields the following hybrids have performed well ICSA 14029 x ICSV-15006; ICSA 14030 x ICSV 15006; ICSA 14305 x ICSV-15006; ICSA 14029 x GGUB 28; ICSA 14030 x GGUB 28; ICSA 14033 x ICSV-15006. Stability analysis was conducted for 16 F1 hybrids at three different locations. In pooled analysis of variance for stability, the genotypes, environments, genotype-environment interaction, environment (linear) and pooled deviations showed significant differences for most of the characters studied. Stability analysis through “Eberhart and Russell’s model” resulted that Bapatla location was found to be most favourable location for brix %, total soluble sugars, ethanol yield and seed yield. Guntur was the most favourable location for number of nodes per plant and juice yield. Garikapadu was the favourable for days to fifty percent flowering, days to maturity, plant height, fresh stalk yield, stem girth, 1000 grain weight and panicle weight. According to AMMI analysis the following hybrids were stable over locations for these characters like H-2 for days to 50% flowering, H-3 and H-5 for days to maturity, H-10 and H-2 for plant height, H-7 and H-5 for no of nodes per plant, H-15 for stem girth, H-3 and H-4 for 1000 grain weight, H-5 for fresh stalk yield , hybrids 12, 10,11, 2 for grain yield, H -7 for brix%, H- 7 & H-8 for total soluble sugars and H-10 and 11 for juice yield and H-2 and 3 for ethanol yield. The classification for Eberhart and Russell’s model and AMMI model was similar for the traits Days to 50% flowering, days to maturity, Plant height, number of nodes per plant. For remaining characters the AMMI classification doesn’t present any similarity with the results obtained by Eberhart and Russell’s model. The stable performing hybrids ICSA 14029 x GGUB 28, ICSA 14035 x GGUB 28 and ICSA 14033 x IS 29308 which are tested in 3 locations may be further tested in All India trials before commercial expoliatation of ethanol production. In the generation mean analysis study of ICSB 14029 x ICSV 15006, mean performance of 6 populations indicated that the F2 means were lesser than the F1 means except for brix per cent and stem girth and between mid-parental values in respect of all the traits except panicle weight, fresh stalk weight, grain yield indicating high degree of inbreeding depression. These results depict the predominant role of non-additive gene action which includes both dominance as well as epistatic interactions. The scaling tests as well as chi square test from joint scaling test were highly significant in the cross ICSB 14029 x ICSV 15006’ cross for 11 characters excluding stem girth and 1000 grain weight, indicating inadequacy of simple additive-dominance model and justifying the use of six parameter model for the detection of gene interactions. The six generation mean analysis carried out for 13 quantitative characters indicated significance of dominance gene effects for days to flowering, plant height, fresh stalk weight, juice yield, grain yield and ethanol yield. Significance of one or more interaction types (additive × additive or additive × dominance or dominance × dominance) in all the 13 traits except nodes per plant, stem girth, 1000 grain weight, total sugars estimation and ethanol yield was observed. Based on the signs of [hˆ] and [lˆ] gene effects, complementary gene interaction was evident in the inheritance of days to 50% flowering, days to maturity, juice yield, ethanol yield, while, duplicate gene xix interaction in the inheritance was evident for plant height, number of nodes per plant, stem girth, panicle weight, 1000 grain weight, fresh stalk weight, brix %, total sugars estimation, grain yield indicating predominantly dispersed alleles at the interacting loci.
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    ThesisItemOpen Access
    GENETIC DISSECTION OF SEEDLING AND REPRODUCTIVE STAGE SALINITY TOLERANCE IN RICE USING SALT TOLERANT CULTIVAR MTU 1061
    (guntur, 2022-08-11) VIJAYA DURGA, K.; SATYANARAYANA, P. V.
    The present investigation was undertaken with an aim to identify salinity tolerance lines in F2 population through phenotyping (seedling and reproductive stages) and genotyping (detect presence of salt tolerance QTLs). The present study entitled “Genetic Dissection of Seedling and Reproductive Stage Salinity Tolerance in Rice Using Salt Tolerant Cultivar MTU 1061” was conducted at Regional Agricultural Research Station, Maruteru, with main objective of development and genotyping of mapping population (234 F2 lines) to identify the chromosomal regions relating to seedling and reproductive stage salinity tolerance and phenotyping of the 234 F2:3 progenies for seedling and reproductive stage salinity tolerance. 234 F2:3 lines derived from a cross between a high yielding salt susceptible rice cultivar Sri Druthi (MTU 1121) and salt tolerant variety Indra (MTU 1061) were evaluated for salt tolerance at both stages namely seedling and reproductive stages using hydroponics and pot culture experiment respectively under salinity stress (EC @ 6 and 12 dSm-1). Data on seven seedling salinity tolerance traits viz., salt injury score (SIS), shoot Na+ concentration, shoot K+ concentration, Na/K ratio, shoot length (cm), root length (cm), shoot dry weight (g) and eight yield contributing traits viz., plant height at maturity, days to flowering, panicle length, number of filled grains per panicle, number of total grains per panicle, spikelet fertility, grain yield/plant and productive tillers per plant were recorded. xvii A set of 234 F2:3 lines were evaluated for salt tolerance at seedling stage in a hydroponics experiment taken up during Rabi 2018-19 and Kharif 2019. The F2:3 population and parents showed a wide range of variation for different morpho-physiological traits in response to salt stress. Based on modified standard evaluation score (1-9) for visual salt injury at seedling stage, one line was highly tolerant, forty were tolerant, one hundred fifteen were moderately tolerant, seventy-one were susceptible and the rest seven were highly susceptible. Whereas, donor parent MTU 1061 showed tolerant (score of 3) and recipient parent MTU 1121 showed susceptible reaction (score of 9). In F2:3, shoot Na+ concentration, shoot K+ concentration, Na/K ratio, shoot length (cm), root length (cm) and shoot dry weight (g) ranged from 11.39 ppm to 40 ppm, 4.52 ppm to 17.94 ppm, 1.50 to 5.00, 6.58 cm to 30.59 cm, 6.42 cm to 19.00 cm and 0.07 g to 2.31 g, respectively. In this study, at seedling stage the F2:3 lines had high Na+ and high K+ concentration in the shoot suggesting that homeostasis between Na+ and K+ plays a key role in the seedling stage tolerance to salt stress. Screening of 234 F2:3 lines at reproductive stage was taken up during Rabi 2019-20 using pot culture experiment. Parents and the F2:3 population showed a high variation for different evaluated yield traits in response to salt stress (EC @ 12 dS/m). Grain yield per plant is the best indicative score for tolerance at reproductive stage. Out of the 234 F2:3 lines, five were highly tolerant (grain yield/plant >2.5 g), forty-five were tolerant (grain yield/plant 1.5 g – 2.5 g) and the rest one hundred eighty-four were susceptible (grain yield/plant <1.5 g). Whereas, donor parent MTU 1061 was highly tolerant (grain yield/plant 2.83 g) and recipient parent MTU 1121 showed susceptible reaction (grain yield/plant 0.72 g). In F2:3, plant height, days to flowering, panicle length, number of filled grains per panicle, number of total grains per panicle, spikelet fertility, productive tillers per plant ranged from 46 cm to 102 cm, 92 to 106, 14 cm to 22 cm, 10 to 296, 116 to 459, 6 to 73 and 2 to 5, respectively. In seedling and reproductive stages, a total of 234 F2:3 lines derived from MTU 1061 / MTU 1121 were evaluated for salinity tolerance. Out of the 234 F2:3 lines only seven lines were tolerant in both stages i.e., in seedling stage based on SIS and NaK ratio, in reproductive stage based on grain yield / plant. The selected lines with salinity tolerance at both the stages will be further advanced and will be evaluated in yield trials under stress and non stress conditions. And selected tolerant F2:3 lines (seven lines) will be valuable material for further fine mapping and introgression into elite genotypes to develop salt tolerant varieties. To identify the chromosomal regions relating to seedling and reproductive stages salinity tolerance, the F2 mapping population (234 F2 lines) was developed by making cross between MTU 1061 (donor) and MTU 1121 (recipient). The two parental lines MTU 1061 and MTU 1121 were screened for parental polymorphism using 1,001 SSR markers spanning all the 12 chromosomes. Among 1,001 SSR markers, 104 markers (10%) were xviii polymorphic. The molecular linkage map was constructed using 104 polymorphic markers spanning a total map length of 2956.12 cM using kosambi mapping function using IciMapping V.4.1 software. QTL mapping was carried out using Interval Mapping (IM), Inclusive Composite Interval Mapping (ICIM) and Interval Mapping for Epistatic Mapping (IM-EPI) methods in both seedling and reproductive stages. QTL analyses were conducted for seven seedling salinity tolerance traits in the F2:3 population using interval mapping (IM) and inclusive composite interval mapping (ICIM). A total of 49 additive QTLs were detected by IM for all seven traits whereas 51 additive QTLs were detected by ICIM. A total of 257 pairs of interactive epistatic QTLs were detected by Interval Mapping for Epistatic Mapping (IM-EPI) method. Forty-nine QTLs detected in IM were same as with ICIM. In both methods (IM and ICIM), out of the 49 QTLs, two novel QTLs for SIS score, four QTLs for shoot Na+ concentration, two QTLs for shoot K+ concentration, 16 QTLs for NaK ratio, 17 QTLs for shoot length, six QTLs for root length and two QTLs for shoot dry weight were detected with phenotypic variance ranging from 0.1% to 11%. Compared to IM method, extra two QTLs (qDWT-6-1 and qDWT-9-1) detected for shoot dry weight on chromosomes 6 and 9 in ICIM method. qDWT-6-1 which had a phenotypic variance of 11% and this QTL was detected in the region between RM50 – RM3431 on chromosome 6 which had LOD ≥ 2. In IM-EPI method, 257 pairs of interactive epistatic QTLs were detected, out of 257 pairs of epistatic QTLs, 32 pairs of QTLs for SIS score, 21 pairs of QTLs for shoot Na+ concentration, 15 pairs of QTLs for shoot K+ concentration, 52 pairs of QTLs for NaK ratio, 60 pairs of QTLs for shoot length, 72 pairs of QTLs for root length, five pairs of QTLs for shoot dry weight. One hundred and ten epistatic QTLs were co-localized with 39 additive QTLs for seven seedling salinity tolerant traits. Among salinity tolerance traits, Na+/K+ ratio, an important ion balancing parameter for the salt tolerance, was controlled by 16 QTLs were mapped on chromosomes 1, 3, 4, 6, 7, 8, 9, 10 and 12 detected by IM and ICIM. All QTLs were with small effects with phenotypic variance ranging from 0.5% to 1%. Out of the 16 QTLs, one of the QTL qNaK-1-1 position was corresponding to Saltol locus on chromosome 1. QTL analyses were conducted for eight yield contributing traits under reproductive stage salinity in the F2:3 population using interval mapping (IM) and inclusive composite interval mapping (ICIM). A total of 32 additive QTLs were detected by IM for all eight traits whereas 25 additive QTLs were detected by ICIM. A total of 201 pairs of interactive epistatic QTLs were detected by Interval Mapping for Epistatic Mapping (IM-EPI) method. Twenty-five QTLs detected in ICIM were same as with IM. Out of 25 QTLs, two QTLs for plant height, two QTLs for days to flowering, seven QTLs for number of filled grains per panicle, two QTLs for number of total grains per panicle, three QTLs for spikelet fertility, seven QTLs for grain yield per plant and two QTLs for productive tillers per plant. Compared to ICIM method, additional seven QTLs were detected in IM method, five QTLs (qDFL-6-1, qDFL-6-2, qDFL-7- xix 1, qDFL-9-2 and qDFL-11-1) for days to flowering, one QTL (qGY-12-1) for grain yield per plant and one QTL (qPT-12-1) for productive tillers per plant. All additive QTLs were minor with a phenotypic variance ranging from 0.2% to 7% detected by IM and ICIM. In IM-EPI method, 201 pairs of interactive epistatic QTLs were detected, out of 201 pairs of epistatic QTLs, eight pairs of QTLs for plant height, 35 pairs of QTLs for days to flowering, five pairs of QTLs for panicle length, 43 pairs of QTLs for number of filled grains per panicle, eight pairs of QTLs for number of total grains per panicle, 38 pairs of QTLs for spikelet fertility, 42 pairs of QTLs for grain yield per plant and 22 pairs of QTLs for productive tillers per plant. Forty-nine epistatic QTLs were co-localized with 19 additive QTLs for six reproductive salinity tolerant traits. At seedling stage, the phenotypic responses, genomic composition, and QTLs identified from the study indicated that Na/K ratio is the key factor for salinity tolerance. The mechanisms of tolerance might be due to homeostasis between Na+ and K+ or Na+ compartmentation. In reproductive stage phenotypic responses and QTLs identification indicated that grain yield per plant under stress is the key factor comparative to remaining parameters such as number of spikelets, filled spikelets and unfilled spikelets. It can be concluded from the study that tolerance at the seedling stage is not necessarily associated with tolerance at the reproductive stage and vice versa. The tolerant F2:3 lines will be a valuable pre-breeding material for use in rice breeding programs and also provide an opportunity for functional genomics studies to provide molecular insights into salt tolerance mechanisms in MTU 1061.
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    ThesisItemOpen Access
    GENETIC ANALYSIS OF YIELD AND ITS COMPONENTS AND PHENOTYPING AGAINST YELLOW MOSAIC DISEASE IN MUNGBEAN (Vigna radiata L. Wilczek)
    (Acharya N.G. Ranga Agricultural University, Guntur, 2021-12-08) SANTHI PRIYA, CHAPPA; RATNA BABU, Dr. D.
    GENETIC ANALYSIS OF YIELD AND ITS COMPONENTS AND PHENOTYPING AGAINST YELLOW MOSAIC DISEASE IN MUNGBEAN (Vigna radiata L. Wilczek)
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    ThesisItemOpen Access
    GENETICS OF ANAEROBIC GERMINATION TRAITS IN RICE (Oryza sativa L.)
    (Acharya N.G. Ranga Agricultural University, Guntur, 2021-12-08) . SUDEEPTHI, K; SRINIVAS, Dr. T.
    The present investigations were undertaken at Regional Agricultural Research Station, Maruteru, West Godavari District of Andhra Pradesh, during 2017-2019. Anaerobic germination screening of 107 rice genotypes revealed MTU 1140, MTU 2716, PLA 1100, RTCNP 28 and RTCNP 50 to be tolerant for anaerobic germination with superior germination per cent, shoot length, root length and seedling dry weight in addition to seedling vigour index and anaerobic response index, compared to other genotypes and hence, were found promising for use in direct seeding under wet conditions. The genetic variability studies revealed narrow difference between PCV and GCV for majority of the traits. High genotypic and phenotypic coefficient of variation along with high heritability coupled with high genetic advance as per cent of mean was exhibited by germination per cent, root length, seedling dry weight, seedling vigour index, anaerobic response index and number of ear bearing tillers per plant. Character association and path studies revealed germination per cent and shoot length to be effective selection criteria for improvement of seedling vigour index, while, number of ear bearing tillers per plant, total number of grains per panicle and test weight were found to be important for improvement of grain yield per plant. The diversity analysis for anaerobic germination traits using Mahalanobis D2 grouped the 107 rice genotypes studied, into nine clusters. The mode of distribution of genotypes was observed to be at random. Hybridization of genotype of cluster IX (MTU 1140) with genotypes of cluster VII (MTU 1010, MTU 1156, NONA BOKRA, SM 10, SM 14) were expected to result in transgressive segregants due to their high diversity. Maximum genetic diversity was contributed by shoot length, followed by seedling dry weight, anaerobic response index, germination per cent and root length. The PCA analysis revealed two principal components with eigen values more than xvii one contributing to 77.662 per cent of the total variability. Further, the study identified germination per cent, shoot length, anaerobic response index and root length as the maximum contributing traits towards the existing variability. Mahalanobis D 2 for yield and yield component traits grouped the 107 rice genotypes into seven clusters. Maximum inter-cluster distance was observed between cluster II and III indicating that genotypes from these clusters were highly divergent meriting their consideration in selection of parents for hybridization. Minimum intercluster distance was observed between cluster VI and VII, while, the genotypes included in cluster IV exhibited maximum intra-cluster distance. Hybridization between MTU 1153, MTU 1156, MTU 1010, MTU 3626, FL 478, MTU 7029, MTU 1001 of cluster II and the genotype, RTCNP 35 of cluster III are expected to result in greater variability and transgressive segregants. Days to 50 per cent flowering contributed maximum to total divergence. The PCA analysis revealed three principal components with eigen values greater than one contributing to 69.412 per cent towards the total variability. Further, the study also identified the maximum contributing traits towards the existing variability as panicle length, days to 50 per cent flowering, number of ear bearing tillers per plant, plant height and test weight. Molecular characterization studies of 107 rice genotypes with 30 anaerobic germination linked SSR markers revealed 18 SSR markers to be highly polymorphic. Further, a total of 49 reproducible polymorphic alleles were amplified with an average of 2.72 alleles per locus with these 18 polymorphic SSR markers. An analysis of the UPGMA (Unweighted Pair Group Method with Arithmetic Mean) based dendrogram revealed grouping of the 107 genotypes into two major clusters. The cluster diagram revealed additional sub clusters (11) in Cluster I. The genotypes, MTU 1140, PLA1100, SM-2 and RTCNP-28 which had recorded more than 80 per cent germination under anaerobic conditions of submergence for 14 days, gave similar amplification bands at 330bp with RM 23877 anaerobic germination linked marker. The markers, RM 23877, RM 6318, RM 17403, RM 5361, RM 6737 and RM 149 with high PIC value were found to be highly informative markers (PIC > 0.50) with potential for identification of anaerobic germination tolerance genotypes. Gene action studies for anaerobic germination traits revealed inadequacy of simple-additive dominance model for majority of the traits studied in most of the crosses, based on the significance of scaling tests A, B and C. In general, dominance effects (h) had exceeded the corresponding additive effects (d) in almost all the crosses. Presence of duplicate type of epistasis was noticed in most of the crosses for most of the traits. Scaling tests and gene action studies for yield and yield component traits also revealed the inadequacy of simple-additive dominance model for majority of the traits studied in most of the crosses. However, the adequacy of simple additive-dominance model was observed for few crosses with respect to number of ear bearing tillers per plant, panicle length and test weight. The results also revealed the pre-ponderance of dominant gene action (h) for majority of the traits in most of the crosses studied. The gene interaction studies revealed the pre-dominance of dominance x dominance (l) gene action for grain yield and majority of the yield traits studied in most of the crosses. Further, duplicate epistasis was noticed for majority of the traits studied in most of the crosses.
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    ThesisItemOpen Access
    GENETIC IMPROVEMENT FOR YIELD AND YIELD COMPONENT TRAITS THROUGH INDUCED MUTAGENESIS IN BLACKGRAM (Vigna mungo (L.) Hepper)
    (Acharya N.G. Ranga Agricultural University, Guntur, 2021-12-06) SREEVALLI DEVI, M.; MOHAN REDDY, Dr. D.
    The present investigation entitled “Genetic improvement for yield and yield component traits through induced mutagenesis in blackgram [Vigna mungo (L.) Hepper]” was carried out during kharif, 2017 (M1 generation), rabi, 2017-18 (M2 generation), kharif, 2018 (M3 generation) and rabi, 2018-19 (M4 generation) at dry land farm of Sri Venkateswara Agricultural College, Tirupati. The study was undertaken to assess the biological efficiency of different mutagens viz., five doses of gamma rays (200 Gy, 300 Gy, 400 Gy, 500 Gy and 600 Gy), five concentrations of Ethyl Methane Sulphonate (EMS) (0.2%, 0.3%, 0.4%, 0.5% and 0.6%) and three concentrations of Maleic Hydrazide (MH) (0.01%, 0.02% and 0.03%) in two blackgram varieties viz., LBG 752 and TBG 104 under in-vitro condition, to determine the effectiveness and the efficiency of various mutagens, to estimate the nature of variability for yield and yield component traits, to study the effects of induced variability on character association using Genotype by Trait biplot analysis and to isolate desirable mutants for yield and yield component traits. The results on LD50 values of various mutagens based on seed germination percentage revealed that, LD50 value for gamma rays in LBG 752 was 500.16 Gy and in TBG 104 it was 552.92 Gy. Similarly, the LD50 value for EMS in LBG 752 was 0.396 per cent and in TBG 104 it was 0.554 per cent. Whereas, the LD50 value for MH in LBG 752 was 0.016 per cent and in TBG 104 it was 0.028 per cent. In M1 generation, the mean values of seed germination (%), shoot length (cm) and root length (cm) under in-vitro condition and seedling emergence, seedling survival, seedling height, pollen fertility, plant height, number of primary branches per plant, number of clusters per plant, number of pods per plant, number of seeds per pod, pod length, seed fertility, 100-seed weight and seed yield per plant under field condition were greatly reduced due to mutagenic treatments. The reduction in these characters under in-vitro condition were found to be more prominent in MH treatments followed by EMS and gamma rays treatments, indicated more biological efficiency of gamma rays than EMS and MH treatments. xviii In M2 generation, 378 progenies of LBG 752 and 368 progenies of TBG 104 selected from all the mutagen treatments in M1 based on healthy and normal appearance were studied by growing them in plant to progeny rows. Three types of chlorophyll mutants viz., albina, xantha and chlorina were observed. viable mutants like cotelydonary leaf mutants, stature mutants, leaf mutants, stem mutants, pod mutants, seed mutants, duration mutants and non-viable mutants like flowered sterile mutants and non-flowered sterile mutants were identified which could be exploited for improving desirable traits into the otherwise well adopted cultivars. Among the mutagens, MH treatments were more effective followed by EMS and gamma rays treatments in both the varieties. The gamma rays were more efficient followed by EMS and MH treatments in both the varieties for inducing chlorophyll and viable mutants on the basis of injury, lethality and sterility except efficiency based on lethality in TBG 104, where MH treatments showed higher value followed by gamma rays and EMS treatments. Data on eleven quantitative traits showed a wide range of variation for most of the traits in mutants, which indicated great scope for improving various quantitative traits through mutation breeding. In M3 generation, 361 progenies of LBG 752 and 270 progenies of TBG 104, selected from all the mutagen treatments in M2 based on superior performance in yield and yield component traits were studied. High GCV, PCV, heritability and GAM estimates were observed for number of primary branches per plant, number of clusters per plant, number of pods per plant and seed yield per plant in all the mutant families of LBG 752 and TBG 104 with few exceptions indicating the preponderance of additive gene action and hence simple selection would be more effective for improvement of these characters. The GT biplot analysis was also conducted to study the effects of induced variability on character association in the selected mutant families which showed varying pattern of trait relationships in the progenies of different families studied. Hence, population dependent association studies could be suggested for effective selection in the mutant families. In M4 generation, a total of 57 progenies, 32 from LBG 752 and 25 from TBG 104, which were selected in M3 were evaluated along with their parents. The mutant lines of LBG 752 viz., LBG 752-17, LBG 752-1, LBG 752-31, LBG 752-12, LBG 752-10, LBG 752-3, LBG 752-11, LBG 752-2, LBG 752-28 and LBG 752-25 and the mutant lines of TBG 104 viz., TBG 104-14, TBG 104-20, TBG 104-12, TBG 104-4, TBG 104-23, TBG 104-25 and TBG 104-3 recorded significantly high per se performance for seed yield per plant suggesting that these mutants could be exploited directly for improving yield. The mutant lines viz., LBG 752-10, LBG 752-11 and LBG 752-12 and TBG 104-14 showed early to maturity besides seed yield per plant. Hence, these lines could be exploited for breeding of short duration lines having high yield advantage. High PCV, GCV, heritability and GAM was recorded for plant height, number of primary branches per plant, number of clusters per plant, number of pods per plant and seed yield per plant indicating the preponderance of additive gene action and hence simple selection would be more effective for improvement of these characters. Based on GT biplot analysis, it was concluded that the traits viz., number of clusters per plant, number of pods per plant, number of seeds per pod, number of primary branches per plant, pod length and 100-seed weight had positive correlation with seed yield per plant. Therefore, the above traits could be considered as the major yield contributing characters in blackgram and emphasis on these traits in the selection programme would give better dividends for yield improvement in blackgram.
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    ThesisItemOpen Access
    STUDIES ON INDUCED MUTATIONS FOR MORPHOLOGICAL, YIELD AND YIELD CONTRIBUTING TRAITS IN MUNGBEAN (Vigna radiata (L.) Wilczek)
    (Acharya N.G. Ranga Agricultural University, Guntur, 2021-12-06) SHAIK. SOFIA, SHAIK. SOFIA; MOHAN REDDY, Dr. D.
    The present investigation entitled “Studies on induced mutations for morphological, yield and yield contributing traits in mungbean (Vigna radiata (L.) Wilczek)” was carried out during kharif, 2017 (M1 generation), rabi, 2017-18 (M2 generation), kharif, 2018 (M3 generation) and rabi, 2018-19 (M4 generation) at dry land farm of Sri Venkateswara Agricultural College, Tirupati. The present investigation was under taken to induce mutations in two mungbean varieties viz., WGG-42 and LGG-460 and to determine the effectiveness and efficiency of various mutagens at different doses/concentrations of gamma rays (200 Gy, 300 Gy, 400 Gy, 500 Gy and 600 Gy), EMS (0.2%, 0.3%, 0.4%, 0.5% and 0.6%) and SA (1 mM, 2 mM and 3 mM). The study was also aimed to estimate the nature of variability, trait associations, direct and indirect contributions of various yield component character towards yield in mutant populations and to isolate desirable mutants for yield and yield component traits. The results on LD50 values of various mutagens based on seed germination percentage revealed that, the LD50 value for gamma rays in WGG-42 was 565.63 Gy and in LGG-460 it was 448.33 Gy. Similarly, the LD50 value for EMS in WGG-42 was 0.46% and in LGG-460 it was 0.42%. Whereas, the LD50 value for SA in WGG-42 was 2.72 mM and in LGG-460 it was 2.01 mM. In M1 generation under laboratory condition, the mean values for germination percentage (%), shoot length (cm) and root length (cm) showed a decreasing trend with increasing dose/concentrations of the mutagens in both the genotypes. The reductions in all these characters were found to be more prominent in SA treatments followed by EMS and gamma rays treatments. Similarly under field condition most of the traits were greatly reduced due to mutagenic treatments. The reductions in all these characters were found to be more prominent in SA treatments followed by EMS and gamma rays treatments. The variety WGG-42 was xix found more sensitive than LGG-460 variety to gamma rays, EMS and SA treatments. In M2 generation, 376 progenies of WGG-42 and 379 progenies of LGG-460 selected in M1 were studied. Three types of chlorophyll mutants viz., albina, xantha and chlorina were observed and occurrence of chlorina was found to be the most frequent. Viable mutants like stature, leaf, duration, cotelydonary leaf, pod, seed size, seed colour and purple colour stem and non viable mutants like non-flowered sterile, flowered sterile and chimeric mutants were identified which could be exploited for improving desirable traits into the otherwise well adopted cultivars. The EMS treatments were found to be more effective and efficient in inducing chlorophyll and viable mutants than gamma rays in both the varieties. Data on eleven quantitative traits showed a wide range of variation and shift in mean values in both positive and negative directions for most of the traits in mutants, which indicated great scope for improving various quantitative traits through mutation breeding. In M3 generation 394 progenies of WGG-42 and 248 progenies of LGG-460, selected in M2 based on superior performance in yield and yield component traits, were studied for yield and yield component traits. High GCV and PCV were observed for number of primary branches per plant, number of clusters per plant, number of pods per plant, pod length and seed yield per plant in both mutant populations. High heritability coupled with high genetic advance as per cent of mean was observed for number of clusters per plant, number of pods per plant and seed yield per plant indicating the preponderance of additive gene action and hence simple selection would be more effective for improvement of these characters. In M4 generation, a total of 55 mutants i.e., 36 from WGG-42 and 19 from LGG-460, which were selected in M3 were evaluated along with their parents. The mutant lines of WGG-42 viz., WGG-42-15, WGG-42-10, WGG-42-12, WGG-42-5, WGG-42-25, WGG-42-33 and WGG-42-29 and the mutant lines of LGG-460 viz., LGG-460-2, LGG-460-19, LGG-460-12, LGG-460-16, LGG-460-8 and LGG-460-3 showed the high per se performance for seed yield per plant suggesting that these mutant lines could be exploited directly for improving yield. The highest 100 seed weight was registered by the mutant line WGG-42-10 followed by WGG-42-28, WGG-42-15 and LGG-460-17, which could be exploited in the hybridization programme as donors for improving bold seeded types. High GCV and PCV was observed for number of primary branches per plant, number of clusters per plant and number of pods per plant indicating the presence of wider variation in mutant lines and high heritability estimates were also recorded for all the eleven characters. High heritability coupled with high genetic advance as per cent of mean was recorded for plant height, number of primary branches per plant, number of clusters per plant, number of pods per plant, pod length and seed yield per plant. Character association analysis revealed that the characters viz., days to 50% flowering, days to maturity, plant height, number of primary branches per plant, number of clusters per plant, number of pods per plant, number of seeds per pod, pod length and 100 seed weight exhibited significant positive association with seed yield per plant. Among these traits number of pods per plant and 100 seed weight had the high and moderate positive direct effects, respectively on seed yield per plant and hence suggested more weightage to these traits in the selection programme to isolate superior lines with high genetic potentiality for seed yield per plant.
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    ThesisItemOpen Access
    ESTIMATION OF COMBINING ABILITY, HETEROSIS AND INBREEDING DEPRESSION FOR GROWTH, YIELD AND ITS ATTRIBUTES IN SUPER EARLY MATURITY GROUP OF PIGEONPEA (Cajanus cajan [L.] Millspaugh)
    (Acharya N.G. Ranga Agricultural University, Guntur, 2021-12-06) SHRUTHI, H. B.; REDDI SEKHAR, Dr. M.
    The present investigation was carried out at ICRISAT to analyze the genetic diversity, combining ability, heterosis and inbreeding depression among super-early pigeonpea genotypes for yield, yield attributes, growth and quality traits. Experimental material composed of thirty-seven super-early pigeonpea genotypes containing 13 determinate types and 21 non-determinate types had been evaluated for genetic diversity using Mahalanobis D2 analysis during Kharif 2016. The selected six diverse parents were crossed in 6 × 6 (Method-2, Model-1) diallel method to identify the good general as well as specific combiners for yield, yield attributes, growth and quality during kharif 2017. The developed F1 crosses, F2 population along with their parents were evaluated for combining ability, heterosis and inbreeding depression during kharif 2018 for the same set of traits. The analysis of variance (ANOVA) for 37 genotypes of super-early pigeonpea revealed significant differences for all the traits under study suggesting the existence of required genetic variation in the material.The close correspondence between the estimates of GCV and PCV indicated the lesser influence of the environment on trait expression. Whereas, high heritability combined with high GAM conveyed the governance of additive genes on trait expression. The ANOVA for dispersion revealed presence of significant pooled aggregate of variation among 37 genotypes of super-early pigeonpea. The hierarchical cluster analysis of the tocher’s method classified 37 super-early pigeonpea genotypes into nine distinctive clusters based on the relative distances (D2 values) from each other. The maximum intracluster distance was found in cluster III followed by cluster V and cluster I depicting lesser genetic diversity within the group making selection ineffective. The higher inter-cluster distance was observed between cluster II and V, V and VIII and in the cluster, I and VIII suggesting wider genetic diversity. Plant height contributed more to the total diversity followed by 100 seed weight. xx The analysis of variance for genotypes, parents, crosses, parents vs crosses for 28 yield, growth and quality traits revealed highly significant mean sum of squares all the traits studied. Analysis of variance for combining ability revealed significant differences, unraveling the presence of adequate genetic variation among 15 cross combinations and parents for all traits except for 100 seed weight. The variance due to GCA and SCA significantly differed for all the traits except for 100 seed weight. The predictability ratio (2 σ 2GCA) ∕ (2 σ 2GCA+ σ 2SCA) neared unity for all the traits signifying the predominance of additive genes for trait expression. However, non-additive gene action governed the expression of net assimilation rate, protein content, phenol content and cooking time in six parents and 15 F1 crosses. As per Arunachalam and Bandopadhyay’s (1979) overall GCA approach ICPL 11301 and ICPL 20333 were identified as good general combiners whereas the cross ICPL 20333 × ICPL 11301 was noted the best cross as per overall SCA approach for yield, yield attributes, growth and quality traits. The crosses depicted desirable heterosis over mid, better and standard check MN 5 for yield, yield attributes, growth and quality parameters. However, the acceptable heterosis over standard check was seen for days to 50% flowering, days to maturity, pods plant-1 and quality traits. The cross, ICPL 20337 × ICPL 11301 followed by ICPL 11255 × ICPL 20333 and ICPL 20338 × ICPL 20333 recorded adequate heterosis over midparent, better-parent and standard checks for seed yield plant-1. Whereas the crosses, ICPL 20333 × ICPL 11301 and ICPL 20338 × ICPL 20333 displayed heterosis for the majority of the growth attributes over the mid, better and standard checks. The crosses ICPL 11255 × ICPL 20333 and ICPL 20338 × ICPL 20333 exhibited significant positive heterosis for protein content, while the crosses ICPL 20337 × ICPL 20333 and ICPL 20337 × ICPL 20338 documented heterosis in a negative direction over the mid, better and standard check for phenol content and cooking time respectively. The yield and yield attributes exhibited higher heterosis and lower inbreeding depression revealed additive gene action governing the trait expression. Whereas growth attributes reported higher heterosis and inbreeding depression exhibiting the non-additive gene action on trait governance. The cross, ICPL 20333 × ICPL 11301 was recognized as the best cross among 15 super-early F1 crosses which exhibited high heterosis and low inbreeding depression for seed yield plant-1 proceeding its suitability for advancement through recombination breeding. Whereas the cross ICPL 20338 × ICPL 11301 exhibited high heterosis and high inbreeding depression and could be exploited through heterosis breeding. The inheritance pattern of plant type and plant height in eight F2 populations of crosses viz., ICPL 20337 × ICPL 20333, ICPL 20337 × ICPL 11301, ICPL 20338 × ICPL 20333, ICPL 20338 × ICPL 11301, ICPL 11255 ×ICPL 20333, ICPL 11255 × ICPL 11301, ICPL 20333 × ICPL 11263, ICPL 11263 × ICPL 11301, was in agreement with 9:7 segregation ratio indicating two dominant genes acting in complementation manner in expression of NDT vs DT plant type as well as tall vs dwarf types in F2 populations. Non-determinate plant type is dominant over determinate plant type while tallness is dominant over dwarf plant height as evident from phenotypes of F1 and segregation in F2 generation. Higher frequency of transgressive segregants were obtained in F2 populations of ICPL 20333×ICPL 11301 (18.98%) followed by ICPL 11255 × ICPL 20333 (14.47%) and ICPL 11255 × ICPL 11263 (7.60%) for seed yield and its attributes. These three crosses could be selected for recovery of transgressive segregants, which could be xxi advanced in single plant progenies through later generations in pedigree breeding for development of high yielding purelines for yield and its attributes. It is to conclude that in novel super-early pigeonpea there exists required genetic variation for yield, yield attributes, growth and quality traits. Combining ability, heterosis and inbreeding depression in the present study revealed the genetic effects and the mode of gene action involved in the trait inheritance. However, the genetic diversity, general combining ability, specific combining ability, heterosis and inbreeding depression in the present investigation were drawn from one location i.e ICRISAT only. Henceforth, the genetic potential of the identified top five crosses i.e, ICPL 20333 × ICPL 11301, ICPL 11255 × ICPL 11301, ICPL 20338 × ICPL 11301, ICPL 20337 × ICPL 11301 and ICPL 11263 × ICPL 11301 are to be extensively tested in different agro-climatic zones for its superiority. If found success, novel super-early pigeonpea genotypes could revolutionize the role of pigeonpea in the cropping system of India under the current scenario with this identified breeding materials.
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    ThesisItemOpen Access
    MARKER ASSISTED INTROGRESSION OF DROUGHT TOLERANCE AND PHOSPHORUS UPTAKE QUANTITATIVE TRAIT LOCI INTO RICE (Oryza sativa L.)
    (Acharya N.G. Ranga Agricultural University, Guntur, 2021-12-06) KAVITHA, GALIPOTHULA; . REDDI SEKHAR, Dr. M
    The present investigation was carried out with breeding material consisting 24 BILs of qDTY3.1 positive lines and 26 BILs of Pup1 positive lines along with two recurrent parents IR58025B and KMR-3R and two QTL donors viz., Apo for qDTY3.1 QTL and Kasalath for Pup1 QTL respectively. The genetic materials of different generations viz., F1, BC1F1, BC2F1 and BC2F2 of two crosses IR58025B x Apo and KMR-3R x Kasalath were developed during kharif 2016 to rabi 2018 by using introgressive backcrossing of marker selected QTL genotypes with recurrent parents involving precise foreground and background selection strategy. RM 520 SSR marker was used for the foreground selection of the qDTY3.1 in F1, BC1F1, BC2F1 and BC2F2 generations of IR58025B x Apo while background selection was performed for the same set of BILs with 88 polymorphic SSR markers. Foreground selection of Pup1 QTL was done with two SSR markers viz., K-46-1 and K-46-2 in F1, BC1F1, BC2F1 and BC2F2 generations of KMR-3R x Kasalath. Inaddition, 86 polymorphic SSR markers were used for background selection in BILs of KMR-3R x Kasalath. The BILs identified from BC2F2 generation of each cross were evaluated in two separate experiments during rabi 2018 at IIRR, Rajendranagar, Hyderabad in a completely randomised block design with two replications under both control (non-stress) and stress condition. The experiment-I consisted of 24 BILs of qDTY3.1 positive lines derived from BC2F2 generation of cross IR58025B x Apo and were evaluated at IIRR, Rajendranagar, Hyderabad during rabi 2018 under both control and reproductive stage moisture stress conditions in order to identify backcross inbred lines with higher grain yield under reproductive stage moisture stress. xv Analysis of variance revealed the existence of significant differences among the BILs in both reproductive stage moisture stress and control conditions for all traits except for panicle length. Correlation analysis revealed highly significant positive association of grain yield per plant with harvest index, filled grains per panicle, spikelet fertility and biological yield per plant under both control and moisture stress whereas plant height, number of tillers per plant, number of panicles per plant, 1000 grain weight, shoot length and SCMR showed significant positive association under reproductive stage moisture stress. Seven BC2F2 introgressive lines viz., GSD-2, GSD-4, GSD-12, GSD-16, GSD-20, GSD-21 and GSD-23 were selected as qDTY3.1 positive lines with higher yield under both control and reproductive stage moisture stress conditions respectively and could be promising donors for improvement of rice cultivars for reproductive stage moisture stress condition. The experiment-II comprised of twenty six Pup1 positive back cross inbred lines (BC2F2) derived from crossing of KMR-3R with Kasalath and were evaluated at IIRR, Rajendranagar, Hyderabad during rabi, 2018 on experimental fields at normal P (> 18.3 ppm) and low P (< 2 ppm) conditions so as to identify the backcross inbred lines with higher grain yield under low P deficient conditions. Analysis of variance indicated the existence of significant differences among the BILs in both low P and normal P environments for all traits except for number of tillers per plant, number of panicles per plant and unfilled grains per panicle. A perusal of character association indicated highly significant positive association of grain yield per plant with harvest index, spikelet fertility and leaf P in both conditions. Number of tillers per plant, number of panicles per plant, filled grains per panicle and leaf P displayed significant positive association with grain yield per plant under low P conditions. Seven BC2F2 introgressive lines viz., GSP-2, GSP-4, GSP-12, GSP-16, GSP-20, GSP-23 and GSP-26 were confirmed as Pup1 QTL positive lines with higher grain yield under both low P and normal P conditions and could be utilized in breeding programme for development of cultivars of rice for low ‘P’ condition.
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    ThesisItemOpen Access
    STUDY OF GENE ACTION FOR GRAIN QUALITY, PHYSIOLOGICAL AND YIELD TRAITS IN RICE (Ovza sativa L.)
    (Acharya N G Ranga Agricultural University, Guntur, 2009) ADILAKSHMI, D; RAGHAVA REDDY, p
    ABSTRACT In 21 cr0sse.s obtained from seven parent diallel, nature of gene action and extent of heterosis were studied for six yield components, five physiological and eleven grain qualit) characters along with yield during rahi 2006-07, kharif2007 - . . and rabi 2007 -08. Gene effects were estimated from six generations of two crosses Genetic parameters like GCV, PCV, heritability and genetic advance were estimated. Combining ability analysis, generation mean analysis, character association, path coefficient analysis and selection indices were also carried out. The phenotypic coefficient of variation was higher than the genotypic coefficient of variation. indicating the profound influence of environment on the expression of characters. The estimates of genetic parameters exhibited higher heritability and genetic advance for all the characters except for ear bearing tillerslplant and panicle length. Thus improvement can be sought by straight selection for these characters. . '.. ' Gca effects were greater than sca effects, non-additive gene action primarily governed almost all the yield components, physiological and quality characters as the sca variance is greater than the gca variance. The estimates of heterosis and heterobeltiosis were variable among crosses in desirable direction and some of them turned out to be best specific crosses. Samba mahsurilprabhat (Ear bearing tillers), samba mahsuril Jagtial samba (1000 grain weight) Samba mahsuri/ Nellore mahsuri (harvest index), Nellore mahsuril Viljetha (head rice recovery). Indra/vi.ietha (LIB ratio) Indralvijetha and Samba mahsurit Polasa prabha (kernel elongation ratio), Samba Mahsurillndra (amylose content), Samba mahsuril lndra (protein content) and IndraIPrabhat ( Iron and Zinc contents) were best specific crosses and exhibited maximum heterosis. These can be used in recombination breeding to spot true breeding progenies. - . Among the parents, Prabhat was good general combiners for most of the yield contributing characters viz.. panicle length. number of seeds per panicle and 1000 grain weight and Prabhat for ear bearing tillerslplant. Samba mahsuri for harvest index and lndra for biological yield were good general combiners among physiological traits. lndra contributed maximum for hulling whereas samba mahsuri contributed highest towards milling trait and important cooking quality trait elongation ratio. Among nutritional quality traits Samba mahsuri and Nellore rnahsuri contributed maxim~rm with intermediate gelatinization temperature and amylose content whereas Nellore mahsuri for protein content. I Additive variance was available for selection in the crosses for Ear bearing tillers (Samba mahsurit Polasa prabha), head rice recovery (Samba mahsuri1Polasa prabha), kernel elongation ratio (Samba mahsuril Nellore mahsuri), Specific leaf weight (Samba mahsuril Polasa prabha and Samba mahsuril Nellore mahsuri) protein content (Samba mahsurimellore mahsuri and Samba mahsuri/Polasa prabha) and grain yield (Samba mahsuri/Polasa prabha' and Sarnaba mahsuri/ Nellore mahsuri). -. - -- For character association Ear bearing tillers, panicle length and 1000 grain weight among the yield component; harvest index, biological yield and flag leaf lU content among physiological traits exhibited positive significant correlation with yield. I J~~lling percent, milling percent and protein content exhibited positive association with yield in case of quality traits. Protein content exhibited negative association with elongation ratio suggesting that, superfine rices are to be upgraded regarding protein content. All the characters under study except days to 50% flowering, panicle length and specific leaf weight exhibited positive direct effect on yield. Keeping in view the significant association along with positive direct effects; Ear bearing tillers, 1000 grain weight, harvest index, biological yield, flag leaf N content, hulling percent, milling percent and protein content can be considered for isolating good genotypes. The association of flag leaf Nitrogen content with days to 59% flowering, plant height, ear bearing tillers, panicle length, number of seeds per panicle, 1000 grain weight. biological yield, hulling percent, milling percent, LIB ratio, protein content, Zinc and yield per plant indicates its significance.