Thesis

Browse

Search Results

Now showing 1 - 9 of 12

Open Access
GENETIC ANALYSIS OF TRICHOME DENSITY IN RELATION TO JASSID RESISTANCE IN COTTON
(University of Agricultural Sciences, Dharwad, 2013-10) MADHURA C.; Dr. M. V. C. GOWDA
The insect pests are the major yield limiting factors in cotton. Bt toxin expressed by Bt-cotton is toxic against bollworms but not against sucking pests especially jassids has become major pests among Bt cotton in India. Pubescence is important and easily recognizable morphological traits which will reduce the leafhopper damage. In the present study genetic variability and interrelationship between pubescence related traits with jassid resistance traits were assessed in germplasm and advanced breeding. High variation and genetic advance was observed for pubescence, trichome length, jassid resistance traits both in germplasm and advanced breeding lines. Correlation Coefficient was found to be highly significant among all the pubescence related traits recorded based on trichome density and pubescence rating in germplasm and advanced breeding lines whereas a strong negative association was observed between pubescence traits and trichome length traits with jassid nymphal count and jassid injury grade. Detailed analysis of germplasm and advanced breeding lines resulted in identification of superior genotypes, BM-1and IGMH-12 with moderately high yield, good GOT, boll weight, lint index and jassid tolerance whereas genotypes TCHH-35102 , NISC-39 R-55 and R-18 were moderately tolerant but with high yield, boll weight and lint index. F2 population exhibited normal distribution for pubescence and trichome length traits indicating quantitative nature of inheritance. The two genotypes of inter-specific F2 mapping population (NISC-37: Pilose X GB-68-Br2: Glabarous) were screened with 29 marker loci reported to be linked with pubescence traits. Twenty two markers were used for construction of genetic maps of LG1 and LG2. Altogether, a total of 11 significant QTLs (LOD more than 3) were identified, which included one QTL each for LWSP, BRHL, BMHL and STHL, two QTLs each for EPSP, ALHL and LMHL, Four QTLs each for ALFP, LFMP, BRTP and BRMP and five QTLS each for ALFPC, LFVP, ALHLC and LVHL.
Open Access
Genetic Enhancement for Drought Tolerance and Durable Blast Resistance in Rainfed Rice (Oryza Sativa L.)
(UAS Dharwad, 2013) Sangodele E.A.; Hanchinal R.R.
The primary objective of this study include screening introgressed population (Swarna x WAB 450 BILs) for physiological and yield component traits under upland condition to identify QTL linked to drought and blast disease, identify top performing BILs tolerant to drought and resistant to blast disease and carry out G x E analysis of selected superior BILs under rainfed condition. One hundred and eighty eight BILs along with 10 checks were screened in pots and on the field in a randomized block design with two replications. Drought stress was imposed at the onset of the reproductive growth phase until grain filling stage by withholding irrigation from the treatment plot until severe leaf rolling was observed. BILs were genotyped with 58 polymorphic SSR markers and marker data were used for the construction of linkage map using QTL IciMapping software. Analysis of variance indicated highly significant differences among BILs for most of the traits under both water stress and non-stressed conditions except harvest index that was significant at 0.05 level of probability. Fifteen QTL were detected for various traits based on composite interval mapping under water stress and non-stress condition with significant contribution from the donor parent, WAB 450. In this study, 10 QTL were detected for physiological, productivity related traits under water stress, whereas, 5 QTL were identified under non stress condition. All identified QTL under water stress for various traits exhibited high phenotypic variance except leaf temperature. WAB 450 contributed all the alleles that enhance drought resistance for all QTL identified in this study except two QTL identified for relative water content and spikelet fertility. Reaction to blast was assayed over the period of two seasons from which 10 BILs were identified as resistant to both leaf and neck blast. WAB 450, BILs No 48, 183 and 188 were identified in the two consecutive seasons as promising lines that were resistant to leaf and neck blast. A number of BILs better than the parents and checks in drought tolerance, blast resistance and G x E interaction were identified as promising for upland ecosystem.
Open Access
Genetic mapping and qtl analysis for disease resistance, yield and quality in groundnut (arachis hypogaea l.)
(UAS Dharwad, 2013) Sujay V.; M. V. C. Gowda
Recombinant Inbred Line (RIL) populations of TAG 24 × GPBD 4 (RIL-4) and TG 26 × GPBD 4 (RIL-5) were phenotypically evaluated and genotyped with SSR markers to construct the linkage map and identify the QTL governing resistance to late leaf spot (LLS) and rust, yield and quality traits in groundnut. Ample variability was observed for both the diseases (LLS and rust) however it was low to moderate for morphological and yield related traits in both the populations. A total of 3,101 and 3,284 SSR markers were screened on parents of mapping populations, of which 211 and 210 markers were considered for linkage map construction. A map of 1982.90 cM with 20 linkage groups (LGs) was obtained for RIL-4 with 190 markers, while RIL-5 had a map of 1963.40 cM with 21 LGs with 182 marker loci. Consensus map was developed with 227 SSR loci of which 144 were common between two maps. It had 20 LGs with genome coverage of 1198.76 cM. QTL analysis with composite interval mapping identified a total of 90 (RIL-4) and 60 (RIL-5) QTLs localized on individual maps. From both the populations, a total of 28 QTLs for late leaf spot, 14 QTLs for rust, 36 QTLs for morphological traits, 29 QTLs for yield and 43 QTLs for quality were identified. Among the 150 QTLs identified, 55 were major QTLs and 95 were minor QTLs. Major QTLs for LLS were identified for the first time in cultivated groundnut and they need to be validated. Presence of major QTL for rust was reconfirmed, and in addition to IPAHM103, a few new markers (GM1536, GM2301 and GM2079) linked to rust resistance were identified and validated in diverse germplasm. Further, FAD2A allele specific marker has been validated and mapped on the genetic map. Tightly linked markers for rust and FAD2A allele for oil quality can be deployed simultaneously in marker assisted breeding in cultivated groundnut.
Open Access
Genetic studies on alternaria leaf spot disease resistance and yield component traits in sunflower (helianthus annuus l.)
(UAS Dharwad, 2013) Sujatha K.; H. L. Nadaf
The present study was conducted to study the inheritance of resistance to Alternaria blight and to improve the agronomic traits of the known source of resistance TX-16R, through induced mutagenesis and hybridization followed by selection at MARS, Dharwad during 2010-12. Inheritance study of resistance to Alternaria helianthi from four crosses, with common donor parent, TX-16R indicated inhibitory gene interaction with 3 resistant: 13 susceptible ratio. Induced mutagenesis of TX-16R with gamma rays at two doses (200 Gy and 250 Gy) and with EMS (0.015 mols/dm3 and 0.020 mols/dm3) was attempted to improve TX-16R for resistance to Alternaria leaf blight and agronomical traits coupled with hybridization programme, of TX-16R was crossed with three male sterile, two maintainer and two restorer lines. Genetic variability among the 159 genotypes derived M3-4/F3-4 lines revealed that GCV and PCV were high for seed yield per plant, 100 seed weight and Alternaria disease reaction. Character association revealed that head diameter and 100 seed weight were significantly and positively associated with seed yield. From the present study recombinant lines 90, (72g), 92 (27.67g) and 133 (32.58g) derived from (CMS 4546A × DSF-2A) × TX- 16R cross, 44 (29.67g) from EMS (0.015 mols/dm3) and 222 (26.5 g) from EMS (0.020 mols/dm3) treatment were identified in M3/F3 and M4/F4 generation for seed yield, of which, recombinant line 133 had high oil content (40.10%) compared to control TX-16R (37.74%). The present study indicated that EMS treatment at 0.015 mol/dm3 and 0.020 mol/dm3 was found to be effective in creating more variability and resulted in isolation of desired mutants compared to 200 Gy gamma radiation. From the hybridization programme, derived lines of the cross (CMS 4546 × DSF-2) × TX-16R performed better for agronomic traits with high Alternaria disease resistance that can be utilized in future hybrid development programme for Alternaria disease resistance.
Open Access
Introgression of foliar disease resistance using synthetic amphidiploids and identification of associated qtls in groundnut (arachis hypogaea l.)
(UAS Dharwad, 2013) Varsha Kumari; M. V. C. Gowda
In an attempt to broaden the genetic base and variability for late leaf spot (LLS) and rust resistance in groundnut, three introgression line (IL) populations, ICGS 76 × ISATGR 278-18 (IL1), DH 86 × ISATGR 278-18 (IL2) and DH 86 × ISATGR 5 (IL3) were developed by crossing disease susceptible varieties with the resistant synthetic amphidiploids (ISATGR 278-18 and ISATGR 5) and backcrossing twice with the recurrent parents. In total 164, 51 and 32 BC2F4 ILs constituted IL1, IL2 and IL3, respectively. Field evaluation of the ILs during kharif 2011, summer 2012 and kharif 2012 showed considerable variability and heritability for disease resistance and most of the agronomic and productivity traits. ILs showed bimodal distribution for LLS, and a normal distribution for rust and agronomic and productivity traits. LLS and rust were negatively correlated, while most of the agronomic and productivity traits were positively correlated. Most of the agronomic and productivity traits exhibited negative correlation with LLS and rust. Linkage mapping with 136 SSR markers in IL1 resulted in map of 1103.2 cM with 19 linkage groups and 8.62 cM inter-marker distance. Single marker analysis showed significant association of a few markers with R2 ranging from 3.94% to 94.34% for LLS and 3.96% to 68.337% for rust. GM1954 was consistent across the populations for both the diseases. Composite interval QTL mapping identified 26 QTL for disease resistance, and 16 for agronomic and productivity traits. Major QTL consistent across seasons included GM1996- IPAHM103 (31.12%-67.45%), gi-4925-GM2144 (9.70%-14.99%) and TC6E01-GM1409 (9.84%-12.39%) for LLS, gi-4925-GM2144 (10.40%-16.52%), GM2009-GM2301 (7.88%- 16.03%) and GM900-GM2082 (5.74%-11.04%) for rust and GM900-GM2082 (13.15%- 24.89%) for test weight. The markers flanking the major QTL carried the favorable alleles contributed by ISATGR 278-18, indicating the utility of wild diploids. QTL and the markers identified here need to be validated before deployed for marker assisted selection.
Open Access
Molecular mapping and marker association studies in diploid cotton (gossypium spp.)
(UAS Dharwad, 2013) Patil Malagouda; B. M. Khadi
Cotton is one of the most important commercial crops grown in India. It is the world’s leading natural fibre crop and is the cornerstone of textile industries worldwide. Inspite of several competitions from synthetic fibres, cotton continues to enjoy a place of prime importance in textile industry. As diploid cottons are well suited to rainfed ecosystem and can fulfil the increasing demand for medium staple nature of fibres, it still necessitates having diploid cottons with improved fibre quality. The present investigation was undertaken to construct the genetic map and to identify QTLs for important yield contributing and fibre quality traits using 50 polymorphic SSR markers in 154 recombinant inbred lines (RILs) derived from the cross between G. herbaceum variety Jayadhar and G. arboreum variety DLSa17. Genetic variability components revealed higher magnitude of variation for most of the traits. This was evidenced by high range and mean performance for different traits in RILs. Per se performance of RILs indicated the improvement over parents for various productivity and fibre quality traits. Association among different traits under study revealed, significant association of seed cotton yield with ginning out turn and lint yield. Fibre length exhibited highly significant positive correlation with fibre strength (0.41) and fibre elongation (0.48). Genetic linkage map was constructed with 50 polymorphic markers. The total map length was 4033.95cM with average distance of 80.68cM between the markers. Out of 15 QTLs detected, seven QTLs were for seed cotton yield. The chromosome 6 harboured QTLs for more than one trait viz., ginning out turn, seed cotton yield, lint yield and uniformity ratio. Three QTLs each corresponding to seed cotton yield, lint yield and uniformity ratio were present between NAU2964 and MUSB1248. The construction of ‘A’ genome diploid map with SSR markers, can serve as a model for the advancement of cotton genetics and genomics. Adding additional markers to the existing map to saturate the map will assist in future map based cloning efforts and fine mapping studies.
Open Access
Genetic Enhancement of Oleic Acid Content in GroundNut(Arachis Hypogaea L.)
(UAS Dharwad, 2013) Gangadhara K; H. L. Nadaf
Investigations were carried out to study the inheritance pattern of high oleic acid and genetic variability for oil quality and agronomic traits in direct and backcross populations of groundnut from 2010 to 2013 at MARS, UAS, Dharwad. Inheritance studies revealed a simple recessive inheritance pattern of high oleic acid content. In F2 generation, individuals segregated in 3:1 (low and medium) ratio in crosses of low × medium and medium × high crosses and 15:1 (low and high) ratio in low × high crosses indicating that high oleic acid content phenotype was governed by two recessive genes in groundnut. This simple duplicatory recessive (ol1ol1ol2ol2) inheritance pattern of high oleic acid content in new sources of high oleic mutants (GM 4-3, GM6-1) and germplasm line ICG 2381 would help to plan for genetic improvement of nutritional and storage stability of groundnut oil. Evaluation of backcross populations for oil quality and agronomic traits indicated the superiority of backcross method for transfer of high oleic acid trait along with other economic traits. In general, higher frequencies of desirable segregants were identified in second backcross derived populations (BC2) compared to direct F2 and first backcross (BC1) populations. The backcross population (GPBD 4 × GM 4-3)-38 × GPBD 4 was superior with higher frequency of desirable recombinants compared to another (GPBD 4 × GM 4-3)-34 × GPBD 4 backcross population. Higher heritability and genetic advance were recorded for oleic acid to linoleic acid ratio, linoleic acid, pod yield per plant, plant height, primary branches per plant, reaction to rust, late leaf spot and Spodoptera litura indicating predominance of additive gene effects .Superior high oleic (>72%) recombinant lines (75-4-3-3 and 76-2-1-5) were identified with better agronomic traits of pod yield and foliar disease resistance that can be tested on large scale over locations for their commercial exploitation.
Open Access
Development and Exploitation of Heterotic pools of Hirsutum and Barbadense for Developing Potential Inter Specific Hybrods, Molecular Marker and Genetic Transformation Study in Cotton.
(UAS Dharwad, 2013) Yanal Alkuddsi; S. S. Patil
Reciprocal selection for improving combining ability was modified to suit cotton and tested. Based on earlier studies DB 533 and DB 534 the selected barbadense elite combiners were crossed and advanced to F4 generation for creating recombinational variability for combining ability against the hirsutum testers (DH 98-27, ZCH 8, 178-24 and DH 18-31). In line x tester study, DB 533 and DB 534 were compared with barbadense lines in developing productive inter specific hybrids. Both of them recorded positive gca effects for seed cotton yield confirming potentiality to form heterotic groups of hirsutum vs barbadense cottons. Of the 23 hirsutum testers, four testers mentioned above exhibited positive gca values for yield. The potentiality of the heterotic box was also confirmed by comparing these eight bench mark crosses with 49 inter specific crosses and checks. Among the 53 F5 barbadense lines, DB 533 x DB 534 F5 IPS 18 showed exceptional superiority for productivity and fiber quality traits. Among three methods of determining pooled score, weighted percent gca approach was efficient in identification of potential combiners. Based on mean and coefficient of variability for productivity DH 98-27 was found to be efficient tester. Sub grouping the F4 lines against pairs of hirsutum testers was done. Among the population used four F4 lines revealed transgressive positive segregation for combining ability against all the four testers and the lines DB 533 x DB 534 F4 IPS 49 and DB 534 x DB 533 F4 IPS 22 were selected for developing sub populations against hirsutum testers. With the help of 40 SSR markers, molecular diversity was assessed and positive correlation was found between genetic distance (GD) and seed cotton yield of F1 and heterosis over checks. In vivo transformation was attempted in hirsutum variety.
Open Access
Studies on Genetic Enhancement of Sugarcane (Saccharum officinarum L.) Productivity for Organic Jaggery Production
(UAS Dharwad, 2013) Somashekhar Guddadamath; B. M. Khadi
The present investigation was taken up to elucidate the information on the variability present in the component traits of cane, sugar and jaggery yield and the amount to which it is heritable. Inter and intra class correlation was also studied across generations. The genetic and molecular diversity to assess the contribution of characters towards the divergence to classify the clones was also studied. Further genotype x environment interaction was studied to assess the relative stability of sugarcane genotypes for productivity triaits of cane, sugar and jaggery yield. The GCV and PCV for total shoots, cane height, internodal length, number of millable canes (NMC), cane yield and HR brix%, were higher, whereas moderate variability was observed for cane girth and single cane weight (SCW). The association studies revealed that, single cane weight, number of millable canes and cane height were the strongest with cane yield. The path analysis shows that, NMC and SCW showed higher direct effect on cane yield. The repeatability studies indicated that NMC, SCW and HR brix% were significantly repeatable across generations. Diversity analysis indicated NMC, SCW and cane height contributed maximum to the total divergence. Molecular diversity using SSR markers detected 95.9 per cent polymorphism and primers NKS 6, 7, 23, 30, 32, 34 and 38 were particularly useful in diversity studies. The stability analysis for cane and jaggery yield revealed that the genotypes viz., SNK 07680 and SNK 07337 and SNK 07658 were stable across environments. Among the genotypes for jaggery quality parameters, SNK 07680 was significantly superior compared to Co 86032 followed by SNK 07337 and SNK 07658. SNK 07680 and SNK 07337 are non flowering across generations and locations, whereas SNK 07658 is very late to non flowering in all the locations studied for flowering behavior.

Thesis

Browse

Thesis Type

Type

Author

Date

Subject

Search Results