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Open Access
SNP Based Linkage Mapping and Qtl Analysis for Fibre Quality and Yield Traits in Gossypium barbadense l. Cotton
(University of Agricultural Science, Dharwad, 2017-06) Mohan Kumar N.V.; Katageri I.S.
Open Access
Studies on Genetic Basis and Molecular Mechanisms of Spot Blotch [Bipolaris sorokiniana (Sacc.) shoemaker] Disease Resistance in Tetraploid Wheat Species
(University of Agricultural Science, Dharwad, 2017-04) Chethana C.K.; V. Rudra Naik
The present investigation was carried out during rabi, 2014-15 at the Agricultural Research Station (ARS), Arabhavi, UAS, Dharwad. The six generation (P1, P2, F1, F2, B1 and B2) mean analysis was used to study the gene action for spot blotch disease resistance in four durum and two dicoccum crosses. High GCV, PCV, heritability and GAM were observed for seed yield, disease severity and AUDPC. The disease severity (%) and AUDPC were negatively associated with seed yield and its components. The duplicate gene action and additive × dominance genetic effects were played an important role in genetic control of spot blotch resistance. The higher percentage of transgressive segregants for disease resistance was observed in F2 population of durum cross Bijaga Yellow × NIDW-295 (15.56 %) and in dicoccum cross DDK-1025 × DDK-50044 (11.00 %). The highly susceptible Bijaga Yellow and resistant NIDW-295 genotypes were analyzed for host pathogen interaction studies at histopathological and molecular level. The infection pattern of Bipolaris sorokiniana at different time points after inoculations was studied. The histopathological studies revealed that six host resistant components viz., number of trichomes on leaves, number of spore per lesion, spore germination, lesion size and lesion frequency were differed in resistant and susceptible genotypes. The expression stability of five housekeeping genes were analyzed by Bestkeeper, gNORM, NormFinder and comprehensive ranking methods suggested that CDC 48 was found most stable and used as reference gene for quantitative RT-PCR. The relative expression profiling of defense related genes during spot blotch infection were analyzed and showed significant up regulation of pathogenesis related (PR) genes, salicylic acid, jasmonic acid, ethylene biosynthesis and transcription factor genes at early stages of infection in NIDW-295 (Resistant) compared to Bijaga Yellow (Susceptible) implying their role in the defense response against spot blotch infection in tetraploid wheat.
Open Access
Genetics of Resistance to Anthracnose in Chilli (Capsicum annuum L.)
(University of Agricultural Science, Dharwad, 2017-12) Rajaput, Sanjeevsingh; Kamatar, M.Y.
The present study was undertaken in chilli crop at Department of Genetics and Plant Breeding, UAS, Dharwad during 2013-15 to study the inheritance pattern for anthracnose disease resistance in the two crosses derived from Byadgi Kaddi and two resistant lines GPM 288-1 and GPM 302-1. Further variability, character association and genetics of yield and component traits were studied. Efforts were also made to demonstrate breeding possibilities of using interspecific hybridization between Capsicum chinense and Capsicum annuum. Segregation pattern in the F2 exhibited ratio of 1:3, indicating that anthracnose disease resistance is governed by single recessive gene, which was further confirmed by segregation ratio of 1:1 in B1 backcross population. The F3 families showing resistance needs to be advanced to further generations to develop inbreed lines with anthracnose disease resistance. High heritability coupled with high genetic advance over means was observed for plant height, number of primary branches, number of secondary branches, number of fruits and dry fruit yield per plant in both the populations. In Byadgi Kaddi  GPM 288-1 and Byadgi Kaddi  GPM 302-1 populations, association of number of fruits per plant and fruit pericarp weight with dry fruit yield per plant was highly positive and significant. Higher estimates for colour, oleoresin and capsaicin content in all F3 lines were noticed. The F1 seeds of cross of C. chinense × C. annuum were incompatible as their hybrid expressed hybrid weakness such as VLS (virus-like syndrome). The presence of significant dominance  dominance type of gene interaction for most of the traits studied indicated that these traits can be utilized in the exploitation of heterosis.
Open Access
Genetic Studies on Abiotic and Biotic Stress Resistance in Maize (Zea mays L.)
(University of Agricultural Science, Dharwad, 2017-10) Mani B.R.; Deshpande, S.K.
Maize inbreds with drought and turcicum leaf blight (TLB) resistance were used in this study conducted at the Department of Genetics and Plant Breeding, College of Agriculture, Dharwad. Thirty one superior inbreds and two testers were crossed in line × tester design to derive 62 test hybrids. Parents, test hybrids and checks (Bio9631, Bio9681, Super 900M) were evaluated for drought tolerance and yield under stress and non-stress conditions during summer 2016 and 2017. Inbreds PDM6529, HKI163 and PDM6576 under stress and HKI163, PDM6518, PDM6529 under non-stress condition were found to be best general combiners while, the crosses PDM4211 × LM13, PDM6547-1 × LM13 and PDM6547-2 × LM13 under stress and PDM6516 × LM17, PDM6547-1 × LM13 and MLB28-1 × LM13 under non-stress condition were best specific combiners for traits related to drought tolerance and yield. Mean yield of the cross PDM4211 × LM13 under stress and non-stress conditions (81.46 q ha-1) was 12.79 per cent superior over best commercial check Bio9631 (72.22 q ha-1). Six generation mean analysis using susceptible (BM125) × resistant (BM135) parents indicated non-additive gene action for TLB resistance. Heterosis breeding approach is suitable to develop resistant hybrids. Of the 146 SSR markers used in the study, three markers viz., bnlg1045, bnlg1940 and mmc0411 were identified to be associated with TLB resistance apart from validating the linkage of marker phi109642 with TLB resistance. The best three general combiners viz., PDM6529, HKI163 and PDM6576 for drought tolerance and yield can serve as donor parents in breeding for drought tolerance these lines can be crossed in diallele fashion to derive superior hybrids. The test hybrid PDM4211 × LM13 with yield superiority has potential for commercial cultivation. New markers bnlg1045, bnlg1940 and mmc0411 linked to TLB resistance can be utilized in marker assisted selection for TLB resistance.
Open Access
Genetic Divergence Studies and Molecular Characterization of Fertility Restorer Genes in Mini Core Collection of Sorghum [Sorghum bicolor (L.) Moench]
(University of Agricultural Science, Dharwad, 2017-08) Prasad, Bhima Hari Vara; Biradar, B.D.
The present study using minicore collection of sorghum (Sorghum bicolor (L.) Moench) has (i) identified maintainers and restorers on Milo and Maldandi source of male sterility, (ii) characterized restorer genes using Rf linked markers, (iii) assessed genetic diversity and (iv) heterotic combinations using diallel crosses. It was conducted during rabi seasons of 2014 to 2017 at Main Agriculture Research Station, University of Agricultural Sciences, Dharwad. Of the 228 genotypes, 43 (25.59 %) were classified as strong restorers (R-lines) with greater than 90 per cent seedset and 22 genotypes (13.10 %) as maintainers (B-lines) with zero seedset on Milo cytoplasm. On Maldandi cytoplasm 19 genotypes (13.87 %) were strong restorers and 37 genotypes (27.01 %) were maintainers. Xtxp250 marker (SSR marker) linked to Rf1 gene at a distance of 1200 bp clearly distinguished B-lines and R-lines on Milo cytoplasm based on the presence or absence of gene. This marker can be utilized in selection of plants with Rf1 gene in segregating populations at the seedling stage itself. D2 analysis grouped 228 genotypes into 22 clusters. Cluster I comprised of maximum genotypes (115) followed by cluster II (45). Inter-cluster distance was maximum between the clusters III and XXI (33.50). Panicle weight contributed more towards divergence (25.64 %). High significant standard heterosis for yield over M 35-1 was exhibited by the crosses BJV-44 × IS 31651 (54.54) and BJV-44 × IS 26025 (38.46). The significant heterosis was observed in B × R crosses rather than B × B and R × R crosses which indicate greater diversity between B and R lines. The genotype IS 31651 was found to be good general combiner for earliness and yield.
Open Access
Studies on Genetics of Qtls for Yield, Yield Component and Fibre Quality Traits in Cotton
(University of Agricultural Science, Dharwad, 2016-08) Nagaraju CH; Khadi, B.M.
To understand the types of gene action controlling sixteen yield, yield component and fibre quality traits in cotton, QTL mapping was performed to dissect the main-effect QTLs (M-QTLs) responsible for the trait performance in 150 recombinant inbred lines (RILs) of interspecific hybrid DCH-32 and two testcross (TC) F1 populations derived from these RILs. Totally, 450 genotypes along with six checks were evaluated at two locations (Dharwad and Devihosur) during kharif 2015 in augmented design. The analyses of variance and the PCV and GCV indicated the presence of wide genotypic and phenotypic variation for all the traits studied. Correlation between seed cotton yield and fibre length and strength were negative. The TC hybrids viz., DRBH-83 x Sahana (3,490 kg/ha) followed by DRBH-56 x Sahana (3,318 kg/ha) and DRBH-32 x Sahana (3,317 kg/ha) recorded significantly higher seed cotton yield compared to check, DHH-11 (2,407 kg/ha). DRBH-63 x Surabhi, recorded significantly higher seed cotton yield (3198 kg/ha) with significantly higher fibre length (29 mm) and strength (27.20 g/tex). The genetic linkage map constructed in RIL populations using Cotton SNP 63K array Bead Chip was utilized for QTL analysis in RILs and TC hybrids. Totally, 95 M-QTLs were identified and classified into two predominant groups, additive QTLs (74) detected primarily in RILs and dominant QTLs [21; 5 (23.80%) from TCF1s of Sahana and 16 (76.19%) from TCF1s of Surabhi] identified exclusively in TC populations. Over-dominant QTL (qSCY-22-1) flanked by i57905Gb and i01031Gh markers (11.96 and 13.33% phenotypic variation) were found common between TCF1 of Surabhi and Surabhi Hmp. In between i38941Gh and i11395Gh markers, three traits viz., lint index (qLI-25-1), ginning outturn (qGOT-25-1) and seed cotton yield (qSCY-25-1) were co-localized on chromosome 25. Genetic effects of these identified QTLs with linked markers have significant implications in genetic improvement of cotton through marker assisted selection.
Open Access
Genetic Analysis of the Traits Related to Mechanical Harvesting in Chickpea (Cicer arietinum)
(University of Agricultural Science, Dharwad, 2016-08) Shridevi B.M.; V. Rudra Naik
The objective of the present study was to assess the genetic variability, inter character association, diversity, gene action and to identify potential cross combinations for the traits related to mechanical harvesting and yield attributes in chickpea. Present investigation revealed considerable variability and heritability for majority of traits. Correlation studies indicated highly significant negative relationship between productivity traits and traits related to mechanical harvesting. D2 analysis revealed that number of seeds per plant, days to maturity and seed yield per plant contributed maximum to the divergence. In total, 58 genotypes were screened and twelve genetically diverse genotypes were selected for developing cross combinations in LxT design. For the traits related to mechanical harvesting, line ICCX 40183 and tester ICCX 40111 were the best general combiners. Genotypes like RVSSG 9, BGD 1068 and Phule G 0215-2 were found to be very good sources of favorable genes for yield related traits. Crosses like AT 2-3 x RVSSG 10 and Phule G 0215-2 x ICCX 40111 were found superior for most of the mechanical harvesting traits. For productivity traits, crosses like GJG 0907 x BGD 1070, GJG 0907 x BG 256 and RVSSG 9 x ICCX 40111 showed significant sca effects. Among 36 crosses, seventeen were evaluated for generation mean analysis. The magnitude of non-additive gene action was predominant in nature with duplicate epistasis for most of the traits studied suggesting development of multiple crosses and raising of large segregating populations followed by intermating of desired segregants could help in enhance the frequency of additive genes. Based on the combining ability studies and performance of F2 crosses, segregants of crosses viz., AT 2-3 x ICCX 40111, RVSSG 9 x RVSSG 10 and RVSSG 9 x BG 256 were found to be potential for combining mechanical harvesting and productivity traits.
Open Access
Germplasm Screening and Genetic Analyses for Drought Tolerance Improvement in Maize (Zea mays L.)
(University of Agricultural Science, Dharwad, 2016-08) Musvosvi, Cousin; Wali, M.C.
Drought is one of the major abiotic challenges to maize production in India and in the world. This study focused on identification and development of drought tolerant germplasm and understanding the genetics of drought tolerance in maize. Hundred inbred lines were screened for drought tolerance and the following were selected: DMR-M-81, M4, FA6, DMR-M-83, GPM36, DMR-M-88, DMR-M-84, M39, M53, FA3, GPM43, and M53. Lines DMR-M-88, FA6, GPM36, M39, and M53 were stable across environments. The twelve drought tolerant lines were involved in half diallel analysis. Pooled (across traits) general combining ability effect (gca) of lines and pooled specific combining ability effect (sca) of crosses were estimated. Good general combiners under drought were: DMR-M-88, M39, FA3, and GPM43. Five among best crosses under drought, namely [FA3 / M39], [GPM43 / DMR-M-88], [DMR-M-84 / DMR-M-83], [FA3 / DMR-M-81], and [DMR-M-83 / FA6], had positive sca effects both under drought and well-watered conditions. Two crosses, [FA3 / M39] and [GPM36 / M4] were high yielding and stable across diverse environments. Genetic distances (GD) among the twelve lines were estimated using microsatellite (SSR) marker data. The correlation coefficient between GD and mid-parent heterosis in respect of grain yield under drought was significant and negative, but low and unreliable for predictive purposes. The correlation coefficients between GD and per se performance and sca were not significant. Lines GPM36, DMR-M-88 and FA6 were good general combiners in a study involving the twelve tolerant lines and two adapted hybrid testers. The testers, BIO-9681 and ARBMH-1 differed in terms of mean testcross grain yields, implying differences in gene frequencies at loci governing grain yield. Regarding interrelationship among traits under drought, grain yield (t ha-1) (GY) was highly and positively correlated with ears per plant, ear length, ear diameter, number of kernels per ear row, number of kernels per ear, and grain yield per plant. Conversely, GY was highly and negatively correlated with drought susceptibility index. In generation mean analysis under drought, additive gene effects were important for inheritance of anthesis-silking interval. For grain yield and its component traits, non-additive gene effects were more important.
Open Access
Development and Evaluation of Turcicum Leaf Blight Resistant Hybrids Using Newly Developed Inbred Lines of Maize (Zea mays L.)
(University of Agricultural Science, Dharwad, 2016-07) Kiran K.K.; G. Shanthakumar
An investigation was carried out to screen 36 maize inbred lines against turcicum leaf blight under artificial epiphytotic condition during kharif 2014 at the Main Agricultural Research Station, UAS, Dharwad. Ten inbred lines showed resistant reaction, of which inbred lines viz., DMIT 105, DMIT 113 and DMIT 118 exhibited lowest terminal per cent disease index and area under disease progress curve which can be considered as slow blighters. Nine inbred lines viz., DMIT 105, DMIT 106, DMIT 111, DMIT 113, DMIT 118, DMIT 121, DMIT 123, DMIT 124 and DMIT 125 based on resistance against turcicum leaf blight, per se performance were selected and crossed to develop 36 single crosses following half diallel mating design. The combining ability analysis revealed presence of higher magnitude of SCA variance than GCA variance indicating predominance of non-additive gene action for most of the traits except kernel rows per cob. The parents DMIT 123 and DMIT 125 were found best for most of yield and its contributing traits as they showed significant gca effects. The crosses, DMIT 105 × DMIT 121, DMIT 118 × DMIT 124, DMIT 121 × DMIT 125 and DMIT 123 × DMIT 125 were found best specific combinations for grain yield with highest sca effects and were found resistant to turcicum leaf blight. The generation mean analysis in the cross DMIT 126 × DMIT 136 indicated duplicate gene action for plant height, kernel rows per cob, kernels per cob, cob weight per plant, hundred grain weight, shelling percentage and grain yield per plant. Single marker analysis in F2 population of the cross DMIT 126 × DMIT 136 revealed Phi 330507 and Umc 1221 markers were closely linked to turcicum leaf blight resistant gene and accounted for 13.77 and 22.72 % of the total variance with LOD of 8.01 and 13.94, respectively.

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