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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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2017 - 201968
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Subject: Genetics and Plant Breeding × End date: 2019 × Start date: 2017 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    VALIDATION OF IDENTIFIED QTLs IN RECOMBINANT INBRED LINES FOR STAGNANT FLOODING TOLERANCE IN RICE.
    (Acharya N G Ranga Agricultural University, Guntur, 2019) SRIKANTH KUMAR, G; GIRIJA RANI, M
    The present study was conducted at Regional Agricultural Research Station (RARS), Maruteru, West Godavari district of Acharya N. G. Ranga Agricultural University (ANGRAU) during Kharif 2018-19 to validate identified QTLs in Recombinant Inbred Lines for stagnant flooding tolerance in rice, to study character association and also effect of one character on the other character for 19 characters. Phenotypic data were recorded for physiological traits (plant survival %, stem elongation at 30 DAT, stem elongation at 60 DAT, flag leaf length, flag leaf width, kneeing ability), lodging related traits (basal internode length, culm diameter, culm thickness, culm strength, per cent of lodging) and yield traits (plant height, days to 50 % flowering, ear bearing tillers plant-1, number of grains panicle-1, panicle length, spikelet fertility, 1000 grain weight and grain yield plant-1). The analysis of variance revealed the presence of significant differences among checks, checks vs genotypes for all 19 characters denoting variability among genotypes. The result implies that RILs exhibit superiority over the susceptible parent Indra for the characters studied. Screening of 167 RILs for stagnant flooding using augmented randomized block design revealed the survival of 146 RILs. Among them, two RILs (SF 7, SF 75) exhibited 100 % plant survival % and 93 RILs exhibited less than 50 % plant survival. These results indicated that plant survival % is essential to realize considerable yields under stagnant flooding. Character association studies revealed that stem elongation at 60 cm, flag leaf length, flag leaf width, basal internodal length, culm diameter, plant height, days to 50 % flowering, ear bearing tillers plant-1, number of grains panicle-1, panicle length, spikelet fertility, 1000 grain weight exhibited positive significant correlation with grain yield plant-1 denoting selection of these traits helps in realizing potential yields under stagnant flooding. Per cent of lodging and kneeing ability showed negative correlation with grain yield plant-1 suggesting that lower per cent of lodging, lower values of kneeing ability are essential to achieve higher yields under stagnant flooding. xii Path analysis revealed that all the yield parameters exhibited positive direct effect on grain yield, all the physiological traits except kneeing ability showed negative direct on grain yield and all the lodging related parameters except per cent of lodging expressed negative direct effect on grain yield. Selection of plants with higher plant survival %, moderate plant height and elongation, high tillering ability having wider and strong culms with longer panicles would be useful for varietal improvement under stagnant flooding. The QTL qSF10.1 affecting plant survival % under stagnant flooding was validated between flanking markers RM 304 and RM 6737 on chromosome 10 with a LOD score of 1.60 explained by phenotypic variance of 7.56 % and additive effect of 7.71 during kharif 2018-19. Fine mapping of previously identified QTL region (RM 304 – RM 6100) using more SSR markers resulted in reduction of QTL region from 166 to 62 kbp. These results implies that QTL region (RM 304 – RM 6737) confers for plant survival %. In addition to validation of QTL qSF10.1, we have also identified 17 QTLs for physiological, lodging related and yield traits with in QTL region. These results were supported by correlation of plant survival % with the physiological, lodging related and yield traits. Out of 17 QTLs, qSE10.1 for stem elongation at 30 DAT, qLOD10.1 for per cent of lodging, qNG10.1 for number of grains panicle-1 and qGY10.1 for grain yield plant-1 with higher values of phenotypic variation can be exploited as major QTLs for yield improvement apart from validated QTL qSF10.1 for plant survival under stagnant flooding.
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    ThesisItemOpen Access
    STUDIES ON ASSOCIATION OF PHYSIOLOGICAL TRAITS WITH YIELD AND YIELD COMPONENT CHARACTERS IN RICE FALLOW BLACKGRAM [Vigna mungo (L.) Hepper]
    (Acharya N G Ranga Agricultural University, Guntur, 2019) ANUHYA, VALLURI; NAGENDRA RAO, K
    The present investigation was carried out at Agricultural Research Station, Ghantasala, Krishna Dt., Andhra Pradesh during Rabi 2018-19 to generate information on the nature and extent of the genetic variability, genetic divergence, correlation and path analysis in 50 genotypes of blackgram for 18 characters viz., days to 50% flowering, days to maturity, plant height (cm), number of branches per plant, number of clusters per plant, number of pods per plant, number of seed per pod, 100 seed weight (g), pod length (cm), seed yield per plant (g), specific leaf weight (g cm-2), leaf nitrogen content (g m-2), total biomass per plant (g), harvest index (%), number of nodules per plant, weight of nodules per plant (mg), leaf area index and specific leaf area (cm2 g-1). Analysis of variance revealed the presence of significant differences among the 50 genotypes for all the traits studied. The genotypes viz., MBG 1069, TGBG 136, VBG 4-14, Buttaminumu and OBG 40 showed higher mean values, high GCV and PCV, high heritability and genetic advance as per cent of mean for yield contributing characters viz., number of branches per plant, number of clusters per plant, number of pods per plant, seed yield per plant among yield characters and total biomass per plant, harvest index, number of nodules per plant and leaf area index among physiological characters suggesting an ample scope for selection of these characters in rice fallow blackgram. Genetic divergence estimated by using Mahalanobis‟ D² statistic, grouped the 50 genotypes into 17 clusters. Out of 17 clusters, cluster I was the largest comprising of 32 genotypes followed by cluster X with three genotypes and the clusters II, III, IV, V, VI, VII, VIII, IX, XI, XII, XIII, XIV, XV, XVI & XVII are solitary (one genotype). The genotypes MBG 1069, TGBG 401, MBG 1050, VBG 13-003 and TADTU 45 have showed maximum inter-cluster distance in Mahalanobis‟D2 analysis, while PCA analysis revealed the genotypes, MBG 1069, TADTU 45, OBG 40 and Buttaminumu as more divergent genotypes. Combining both D2 and PCA, the genotypes MBG 1069 and TADTU 45 are viewed as more divergent. xiv Genotypic correlations in general were higher than phenotypic correlations indicating that the apparent associations are largely due to genetic reasons. The traits days to 50% flowering, plant height, number of clusters per plant, number of pods per plant, number of seeds per pod, 100 seed weight, pod length, leaf nitrogen content, harvest index, number of nodules per plant, weight of nodules per plant and leaf area index were found to possess significant positive association with grain yield per plant at both genotypic and phenotypic levels, thus revealing the possibility of simultaneous selection of all these characters for yield improvement. Path coefficient effects can be concluded as high direct effects were shown by days to 50% flowering, number of pods per plant, total biomass per plant, harvest index and number of nodules per plant at phenotypic level. High direct effects for days to maturity, plant height, number of seeds per pod, total biomass per plant, harvest index, weight of nodules per plant are shown at genotypic level. The character number of pods per plant showed high genotypic and phenotypic coefficient of variation, high heritability, high genetic advance as per cent of mean, higher positive significant correlations with seed yield per plant and higher positive direct effects. Hence, number of pods per plant could be considered as most efficient selection criteria for yield improvement in rice fallow blackgram.
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    ThesisItemOpen Access
    MOLECULAR CHARACTERIZATION OF ELITE GENOTYPES FOR SALINITY TOLERANCE IN RICE (Oryza sativa L.)
    (Acharya N G Ranga Agricultural University, Guntur, 2019) HRUDAYA RAJ, K; SRINIVAS, T
    The present investigation was carried out to evaluate and characterize 80 rice genotypes for seedling and reproductive salinity tolerance and also to study character association for reproductive salinity tolerance parameters, namely, grain yield and yield components and salinity score at seedling stage under saline conditions. The investigation was undertaken at Regional Agricultural Research Station, Maruteru during kharif 2016. The analysis of variance revealed significant differences among the genotypes for all characters studied. Phenotyping of the genotypes for reproductive and seedling salinity tolerance revealed the superiority of Nonabokra and Pokkali. Hence, these genotypes are identified as promising salinity tolerant lines with both seedling and reproductive salinity tolerance. The results on character associations between reproductive salinity tolerance parameters, namely, grain yield and yield components and seedling salinity scores revealed positive and significant association of grain yield with panicle length, number of filled grains per panicle, ear bearing tillers per plant and 100-seed weight under saline conditions. The study of 80 genotypes for their molecular diversity with 14 SSR markers revealed that banding pattern of MCM-41, MCM-48, MCM-100, MCM-223, MLT-5, MLT- 7, MTU-1064, MTU-2077, MTU-3626, MTU-1078, MTU-1153, MTU-1156, FL-478 was analogous to Pokkali (wild donor) and Nonabokara (salinity tolerant variety) at 180bp with RM10793on chromosome 1. The genotypes, MCM-41, FL-478, CST-9, MTU-1078, Pokkali and Nonabokra showed similar amplicon size of 210 bp and were distinct from banding pattern of remaining genotypes with the SSR marker, RM10964. xiii Among the markers used for study of diversity, marker RM 10793 reported highest PIC value of 0.838 followed by RM 10694 (0.763), RM 20224 (0.637) and RM 518 (0.603). RM 10793 showed maximum number of four alleles along with RM 10694 (4) followed by RM 20224 (3), RM 492 (3). Cluster analysis and dendrogram for the 80 genotypes by UPGMA (Unweighted Pair Group Method with Arithmetic Averages) revealed distribution of the 80 genotypes into two major clusters. Cluster I comprised of three sub clusters, while, Cluster II comprised of two sub clusters. Most of the salt tolerant varieties viz.,Pokkali, Nonabokra, CSR -27 were grouped in sub cluster II B. It is concluded that Pokkali and Nonabokra, genotypes can be used as donor for varietal improvement or for introgression of salinity tolerance into a susceptible variety.
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    ThesisItemOpen Access
    IDENTIFICATION OF NOVEL QTLs FOR BPH TOLERANCE IN RICE (Oryza sativa L.) USING RESISTANT DONOR BM 71 (MTU ITJ 206-7-4-1)
    (ACHARYA N G RANGA AGRICULTURAL UNIVERSITY, GUNTUR, 2019) SUNEEL KUMAR, GANTA; RAVI KUMAR, B. N. V. S. R.
    The current research study was carried out during kharif, 2018 at Regional Agricultural Research Station, Maruteru, Andhra Pradesh with one hundred and forty two RILs and two checks to study the variability, heritability and genetic advance for yield and yield contributing traits and to identify QTLs for BPH tolerance. The ANOVA explained significant differences among the RILs for all traits viz. days to fifty percent flowering, plant height (cm), number of ear bearing tillers per plant, panicle length (cm) and grain yield per plant (g) indicating sufficient genetic variability among the RILs. Both GCV and PCV were higher for grain yield (g) per plant and high heritability accompanied with high genetic advance as percent of mean was observed indicating presence of additive gene action in inheritance of this trait and therefore direct selection is effective. Moderate heritability and genetic advance as percent of mean was recorded for plant height (cm) and ear bearing tillers per plant indicating presence of both additive and non additive gene actions. Moderate heritability with low genetic advance as percent of mean was observed for days to 50% flowering and panicle length (cm) indicating non additive gene action and selection may not be effective for the above traits. Evaluation of one hundred and forty two RILs for BPH tolerance was done in both lab and filed conditions. The results revealed that in lab screening forty four RILs were resistant, sixty two were moderately resistant, thirty were moderately susceptible and six were susceptible, whereas in field screening sixty seven RILs were resistant, thirty four were moderately resistant, twenty one were moderately susceptible, twenty were susceptible. Construction of linkage map and QTL analysis, using seventy seven polymorphic markers, revealed that composite interval mapping and interval mapping has identified three QTLs for BPH tolerance viz., qmbph2.1, qmbph4.1 and qmbph12.1 on chromosomes 2, 4 and 12 respectively. In addition to above three QTLs, two more QTLs, qmbph5.1 and qmbph7.1 were identified by interval mapping on chromosomes 5 and 7 respectively. Fine mapping of the above QTLs and identification of putative genes will be the future line of the present study.
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    ThesisItemOpen Access
    CHARACTER ASSOCIATION AND SELECTION INDICES IN FOXTAIL MILLET [Setaria italica (L.) Beauv.]
    (Acharya N G Ranga Agricultural University, Guntur, 2019) PAVANI, ALLU; RATNA BABU, D
    The present investigation was carried out with the prime objective of knowing the character association between different yield and component traits and construction of the best possible selection index for selection of superior genotypes in foxtail millet. To achieve the above objectives, an experiment was conducted at RARS, Lam, Guntur with sixty foxtail millet genotypes during kharif, 2018. The analysis of variance indicated significant differences among 60 genotypes for majority of traits viz., days to 50% flowering, panicle length, productive tillers per plant, days to maturity, iron, zinc, copper, manganese, phosphorus and grain yield per plant indicating a high degree of variability in the material. Phenotypic and genotypic coefficient of variation also indicated the presence of considerable amount of variability for majority of the characters studied. The estimates of heritability and genetic advance as per cent of mean were high for the characters viz., days to 50% flowering, plant height, panicle length, test weight, protein, carbohydrate, calcium, iron, zinc, copper, manganese, phosphorus and grain yield per plant indicating the probable operation of additive gene action in inheritance of these traits and simple selection is sufficient to improve these traits. High heritability coupled with moderate genetic advance as per cent of mean was observed for days to maturity. While moderate heritability coupled with high genetic advance as per cent of mean was observed for productive tillers per plant. Genotypic correlations in general were higher than phenotypic correlations indicating that the apparent associations are largely due to genetic reasons. The traits, test weight, productive tillers per plant, panicle length, carbohydrate and plant height were found to possess significant positive association with grain yield per plant at both genotypic and phenotypic levels. Further, path analysis revealed that test weight, xii productive tillers per plant, panicle length, carbohydrate and plant height showed true relationship with grain yield per plant by establishing significant positive association and positive direct effect at both genotypic and phenotypic levels. Considering the nature and magnitude of character associations and their direct and indirect effects, it can be inferred that test weight, productive tillers per plant, panicle length, carbohydrate and plant height could serve as important traits in any selection programme for selecting high yielding genotypes in foxtail millet. Simultaneous selection taking all characters into consideration was carried out for all the sixty genotypes of foxtail millet and found that Ise 238, Ise 1511, Ise 49 and Ise 132 recorded relatively higher selection index values in the both cases i.e., when the equal economic weights were assigned as well as when inverse of means are used as economic weights for estimation of selection index scores. These results indicate that these four genotypes are superior compared to all other genotypes when simultaneous selection for all the characters was carried out. Restricted selection was carried out by restricting the selection for only fourteen out of fifteen characters without effecting any change in the fifteenth character. In all such fifteen possible restriction selections, the trait plant height recorded maximum estimate of genetic advance in 11 out of 15 cases. This phenomenon was observed in both cases i.e., when equal economic weights are used as well as when inverse of means are used as economic weights of the respective characters. In the process of constructing the suitable selection index for selection of superior genotypes in foxtail millet, maximum estimate of genetic advance over grain yield per plant was obtained when all the fifteen characters under study are included in the construction of selection index. And addition of characters one by one in the selection index constructs resulted in increasing trend of genetic advance values. The best construct was same, when both types of economic weights are used. Further the increasing trend of genetic advance with addition of traits was also similar when both types of economic weights are used. It can be concluded that the best possible construct of selection index for selection of superior genotypes in foxtail millet should include all the fifteen characters which were considered for present investigation. Further, in the process of assigning economic weights to different traits for estimation of score or selection index values to different genotypes as well as in estimation of genetic advance values of different characters and even during restricted selection, it was found that the both ways of assigning the weights i.e., by taking equal economic weights as well as by using inverse of means of respective characters as economic weights are equally effective and resulted in similar conclusions.
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    ThesisItemOpen Access
    MAPPING OF QTL FOR ANAEROBIC GERMINATION USING THE DONOR AC39416A IN THE GENETIC BACKGROUND OF SWARNA SUB-1 (Oryza sativa L.)
    (Acharya N G Ranga Agricultural University, Guntur, 2019) SAIMOHAN, BOLLINENI; CHAMUNDESWARI, N
    The present investigation entitled “Mapping of QTL for anaerobic germination using the donor AC39416A in the genetic background of Swarna Sub-1 (Oryza sativa L.)” was carried out during Kharif and Rabi 2018-19 at RARS, Maruteru, Andhra Pradesh. The objectives of study are phenotypic screening of F2:3 mapping population of Swarna Sub1/AC 39416A, parental polymorphism survey between parents using SSR markers and mapping of QTLs for anaerobic germination in the donor AC39416A. The analysis of variance of phenotypic screening experiment revealed significant differences for all the parameters viz., anaerobic germination (%), plant survival (%), seedling shoot length (cm) and seedling root length (cm), studied using 188 F2:3 mapping population of Swarna sub1 / AC39416A. Parental polymorphism survey between Swarna sub1 and AC39416A revealed 134 (19.42%) out of 687 SSR markers were polymorphic. Out of 134 markers studied only 83 SSR markers have shown clear distinct polymorphic bands. The level of polymorphism ranged from 7.58% to 27.59% with an average of 19.42% for all the chromosomes. The polymorphism percentage was reported to be highest in chromosome 2 (27.59%) while lowest (7.58%) in case of chromosome 9. The DNA extracted from a set of 188 F2 population of Swarna sub1 / AC39416A along with the parents was screened with 83 SSR markers and the genotypic data was used for linkage analysis for studying their segregation pattern of trait under consideration. Linkage analysis was performed using the integrated software called QTL IciMapping software version 4.1.0 and constructed linkage map using 83 polymorphic SSR markers. The length of linkage map across whole genome was 3600.8 cM. QTL analysis was done by two mapping methods namely Inclusive Composite Interval Mapping for the additive QTL (ICIM-ADD) and Single Marker Analysis (SMA) with genotypic data from 188 F2:3 population of Swarna Sub1/AC39416A using a total of 83 SSR markers. xiv In single marker analysis, six markers viz., RM 15554, RM 401, RM 5711, RM 21700, RM 28073 and RM 1584 which are located on chromosome 3, 4, 7, 7, 12 and 12 respectively were found to be linked with anaerobic germination and accounted for a total of 4.2% to 10.01% phenotypic variance (R2). Highest phenotypic variance (10.018%) was recorded on chromosome 12 by qAG12-1 with peak marker RM 1584. In Icimapping (ICIM) method a total of seven QTLs were identified viz., qAG2, qAG3, qAG7-1, qAG7-2, qAG9, qAG10 and qAG12. Out of 7 QTLs found, 2 QTLs were located on chromosome 7, 1 QTL on each of the chromosomes 2, 3, 9, 10 and 12. All these 7 QTLs explained phenotypic variance of about 37.47% collectively for AG trait, with their individual contributions ranging from 3.5% to 8.66% of phenotypic variation and LOD scores of 2.6 to 5.85. The phenotypic variance explained by qAG2, was highest (8.66%) followed by qAG10 (8.60%) which were mapped on chromosome 2 and 10 respectively, whereas, the highest LOD score (5.85) was shown by qAG10. Of the total QTLs identified for AG in the present study, qAG4 and qAG10 are novel QTLs and remaining QTLs were previously identified by earlier workers. Hence, based on the QTLs identified for AG in the present investigation and QTLs identified by earlier workers it is concluded that the QTL qAG12-1 can be considered as major QTL governing germination under anaerobic conditions. Hence, the QTL qAG12-1 can be introgressed into popular rice varieties for development of varieties tolerant to submergence during germination which is the need of the hour for good crop stand establishment in direct seeding fields and paddy nurseries.
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    ThesisItemOpen Access
    GENETIC DIVERGENCE FOR FIBRE YIELD AND YIELD COMPONENTS IN ROSELLE (Hibiscus sabdariffa L.)
    (Acharya N G Ranga Agricultural University, Guntur, 2019) KRANTHI PRIYA, PARUPUDI; HARI SATYANARAYANA, N
    The present study was conducted at Agricultural Research Station, Amadalavalasa during kharif, 2018 to study the genetic variability, heritability, genetic advance, correlation, path analysis and genetic divergence in 52 roselle genotypes for the 11 characters viz., days to 50 per cent flowering, plant height (cm), base diameter (mm), mid diameter (mm), petiole length (cm), number of nodes per plant, internode length per plant (cm), green fresh weight per plant (g), dry stick weight per plant (g), fibre wood ratio and fibre yield per plant (g). In addition, data was also collected for mealy bug and foot and stem rot incidence for screening of genotypes for pest and disease incidence. The analysis of variance revealed significant differences among 52 genotypes for all the characters included under study. High variability and high heritability coupled with high genetic advance as percent of mean was observed for green fresh weight per plant, dry stick weight per plant and fibre yield per plant indicating preponderance of additive gene action of these characters. Hence, the improvement can be achieved by simple direct selection for these characters. Genotypic correlations in general were higher than their corresponding phenotypic correlations indicating masking effect of environment. The traits plant height, base diameter, mid diameter, petiole length, number of nodes per plant, green fresh weight per plant, dry stick weight per plant and fibre wood ratio showed significant positive association with dry fibre yield per plant at both phenotypic and genotypic levels and path analysis studied revealed that the traits dry stick weight per plant, and fibre wood ratio recorded high positive direct effects both at phenotypic and genotypic levels. xiii Considering nature and magnitude of character associations and their direct and indirect effects, it can be infereed that green fresh weight per plant, dry stick weight per plant and fibre wood ratio may be helpful in evolving the high fibre yielding varieties in roselle. By using Mahalanobis D2 analysis genotypes were grouped into 15 clusters. Cluster I was the bigger comprised of 23 genotypes followed by cluster II with 16 genotypes and cluster III to XV had single genotype each and showed nil intra cluster D2 values. The maximum contribution towards genetic divergence was by green fresh weight per plant (24.21) followed by fibre wood ratio (23.68). The cluster means of the characters in which the maximum plant height, base diameter, mid diameter, petiole length, green fresh weight, dry stick weight per plant and fibre wood ratio showed highest for cluster XIV whereas lowest in cluster XV. Highest inter cluster distance was observed between cluster XIV and XV (1901.38) followed cluster X and XV (1812.20) and cluster XII and XIII (1467.66) indicating there was a wider genetic variability present among the genotypes. The maximum amount of heterosis can be expected from the crosses with parents belonging to clusters with maximum inter cluster distance. Selection of parents from such clusters for hybridization programmes help to achieve novel especially transgressive segregants. By conducting screening studies on mealy bug and foot and stem rot incidence it was revealed that, out of 52 genotypes studied, three genotypes (RIN-018, RIN-020, RIN-026 ) were found to be tolerant / moderately tolerant to mealybug and moderately resistant to foot and stem rot disease. In the present investigation, the genotypes RIN-018, RIN-020, RIN-026 and RIN-050 were found to be highly diverse and may serve as potential parents for future hybridization programmes.
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    ThesisItemOpen Access
    IDENTIFICATION OF GENOMIC REGIONS LINKED TO DORMANCY RELATED TRAITS IN RICE (Oryza sativa L.)
    (Acharya N G Ranga Agricultural University, Guntur, 2019) BALA KANAKA VENKATA MANI, D; KRISHNAVENI, B
    The present investigation was carried out during kharif, 2018 at Agricultural College Farm, Bapatla with 119 recombinant inbred lines along with parents (BPT 2231 and MTU 1001) to elicit information on the nature and extent of variability, heritability, genetic advance for yield, yield components and identification of genomic regions linked to dormancy related traits in rice. The analysis of variance indicated significant differences among RIL population along with parents for majority of traits studied indicating that the data generated from the above material shall represent wide variability. The estimates of phenotypic coefficient of variation for all the characters under study were high than the genotypic coefficient of variation and the variation is less between these two estimates indicating meager influence of environment on the expression of these traits. The results of genetic parameters among yield components and dormancy related traits revealed high heritability coupled with high genetic advance as per cent of mean for number of ear bearing tillers per plant, grain yield per plant, germination (%) at 5 days and 10 days after harvesting, free amino acid (mg/100g) and total soluble sugars (mg/100g) indicating the operation of additive gene action in the inheritance of the trait. Hence good response to selection can be anticipated for improvement of these traits. Identification of genomic regions/QTL involves comparative studies on phenotyping and genotyping data of large mapping populations. The phenotyping studies were conducted at 5 days and 10 days after harvesting. Based on the germination (%), the entire RIL population was divided into 3 categories viz., strongly dormant lines (germination below 50%) moderately dormant lines (germination 50-79%) and weakly dormant lines (germination above 80%). Among all these, the line SD 12 exhibited below 10% of germination whereas the dormant parent MTU 1001 recorded 25% germination at 10 days after harvesting. Hence, this can be exploited in future breeding programme as this line also recorded on par with grain yield when compared with parents. Among the RIL‟s under study, 7 lines viz., SD 20 (37.94 g), SD 30 (36.75 g), SD 32 (39.13 g), SD 45 (41.27 g), SD 59 (41.74 g), SD 65 (41.02 g) xiii and SD 80 (39.75 g) which recorded significantly superior grain yield than the parents coupled with strong dormancy period of 10 days may be tested for their suitability in coastal regions in during kharif season in future breeding programmes. The parental polymorphism survey was conducted with 188 SSR markers including 72 trait linked and 116 random markers distributed all over 12 chromosomes of rice. Among these, 10 markers manifested polymorphism between the parents with difference in the length of amplified product which is high for marker RM22565 followed by RM3295 and RM346. The contrasting bulks for the target trait were prepared (i.e., Low dormancy bulk and High dormancy bulk) based on the germination (%) at 5 days and 10 days after harvesting and physiological parameters i.e. free amino acids and total soluble sugars of RIL population. Out of these 10 polymorphic markers screened, four markers viz., RM346, RM22565, RM7051 and RM10793 co-segregated among the individual recombinant inbred lines constituting respective bulks. Hence, these four markers were used for genotypic studies of RIL population. The genotyping studies of RIL population revealed that the RM22565 recorded 60% similarity between the phenotyping and genotyping. Among the RIL population under study, three lines viz., SD 3, SD 15 & SD 113 manifested similar amplicon size with the dormant parent MTU 1001 when amplified with two markers viz., RM346 and RM7051. Likewise, four lines viz., SD 55, SD 68, SD 72 and SD 113 exhibited similar banding pattern with MTU 1001 when amplified with RM346 and RM22565. The line SD 113 also manifested similar banding pattern with that of MTU 1001 when it was amplified with 3 markers viz., RM346, RM22565 and RM7051 while SD 72 and SD 87 exhibited similar bands with RM346, RM22565 and RM10793. Among the 119 RIL population studied, one line i.e. SD 12 manifested banding pattern as that of the dormant parent MTU 1001 with all the four polymorphic markers viz., RM346, RM22565, RM7051 and RM10793. Considering both phenotyping as well as genotyping studies and bulk segregant analysis, it may be concluded that the identified recombinant inbred lines which showed high dormancy also exhibited similar banding pattern as that of dormant parent MTU 1001 with four markers viz., RM346, RM22565, RM7051 and RM10793 on chromosome 7, 8, 4 and 1 respectively indicating that these chromosomal regions may be harboring the genes/QTL‟s responsible for the strong dormancy in the above lines. Among the polymorphic markers used in the parental study, one marker i.e. RM346 was identified and used as dormancy linked marker in previous studies. But the other 3 markers viz., RM22565, RM7051 and RM10793 were not reported in the earlier studies and hence these three markers may be identified as novel markers linked to dormancy trait suggesting that these markers may also be utilized as linked markers for dormancy related traits in marker assisted breeding programmes. The entire genotypic data was scored and analyzed using single marker analysis to know the marker trait association. The marker RM22565 (P<0.0001) on chromosome 8 reported significant association with germination (%) at 5 days after harvesting at a mapping position of 5,796,298-5,796,574bp (5 cM) using single marker analysis. Hence, it may be concluded that the chromosomal region linking to marker RM22565 on chromosome 8 may be associated with the genes linked to the dormancy related traits and it‟s usefulness in the marker assisted selection to screen the genotypes/cultivars to identify the strongly dormant genotypes.
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    ThesisItemOpen Access
    STUDY OF GENETIC DIVERSITY IN ELITE INBRED LINES OF MAIZE [Zea mays L.]
    (ACHARYA N G RANGA AGRICULTURAL UNIVERSITY, GUNTUR, 2019) MALLIKARJUNA, SANIKOMMU; ROJA, V
    The present investigation was carried out during kharif 2018-19 at Agricultural Research Station, Peddapuram with the prime objective of categorizing 49 genotypes of maize (Zea mays L.) into distinct classes based on their genetic diversity. Other parameters like mean, genetic variability, heritability, genetic advance as per cent of mean, character association and the magnitude of direct and indirect effects of yield component traits on grain yield were also studied. The analysis of variance demonstrated significant differences among 49 genotypes for all the traits investigated. The traits, days to 50 per cent tasseling, days to 50 per cent silking, days to maturity, plant height and ear placement height recorded a slight difference between Phenotypic Coefficient of Variation (PCV) and Genotypic Coefficient of Variation (GCV) indicating less influence of environment on these characters whereas traits like anthesis silking interval, kernels row-1, cob yield plant-1, grain yield plant-1 and protein content registered wide variation between PCV and GCV suggesting more influence of environment on the expression of these traits. High heritability coupled with high genetic advance as per cent of mean was observed for ear placement height whereas anthesis silking interval, cob yield plant-1 and grain yield plant-1 registered low to moderate heritability and high genetic advance as per cent of mean was observed for the trait implying additive gene action. Futher, the traits days to 50 per cent tasseling, days to 50 per cent silking, days to maturity and plant height recorded high heritability coupled with low to moderate genetic advance as per cent of mean implying non-additive gene action in the expression of these traits. Genotypic correlations in general were higher than phenotypic correlations indicating associations are largely due to genetic reasons. The traits, cob length, cob girth and cob yield plant-1 were found to possess significant positive association with grain yield plant-1 at both phenotypic and genotypic levels. xi Path analysis revealed that cob yield plant-1 showed true relationship with grain yield plant-1 by establishing significant positive association and positive direct effect. Considering the nature and quantum of trait associations and their direct and indirect effects, it can be inferred that plant height, cob length, cob girth and cob yield plant-1 could appear as key traits in selection programme for picking up high yielding genotypes for the utilization in the breeding programme. The multivariate analysis indicated considerable genetic divergence among the 49 genotypes studied. D2 analysis grouped the 49 maize genotypes into nine clusters and cluster I was largest with 24 genotypes while clusters IV, VI, VII, VIII, IX are smallest with single genotype in each. Maximum inter cluster distance (110.57) was observed between clusters II (KDML-115, PDML 15, VM 51, ADL 1619, PDML7470, CAL 1784, CAL 17834, VM 45, AL8127) and cluster VIII (CML 1505) indicating presence of maximum diversity among the genotypes falling within these clusters. Principal component analysis revealed first five principal components recorded eigen value more than one explained 75.39 per cent of the total variability. 2D, 3D scatter diagram of principal component analysis demonstrated that genotypes like ADL8070, PDML 19-39, VM 51 and CML 1505 are away from other genotypes which is also evident from tocher‟s method proving that these genotypes are more divergent and indicating their usefulness in hybrid breeding programmes. Hence, the crosses VM51 × CML1505 and ZL161032 × PDML19-44 are having good chance of producing heterotic hybrids or transgressive segregants. Further, these genotypes should be tested for their combining ability and gene action using different mating designs to produce hybrids based on the type of gene action involved.