SURENDER RAJU, CHKRISHNA, LAVURI2016-09-142016-09-142014http://krishikosh.egranth.ac.in/handle/1/76547The present investigation was conducted to estimate the combining ability, heterosis, inbreeding depression, heritability, variability, genetic advance, correlations and path coefficients for yield components and grain quality characters crossing 8 parents in diallel design (without reciprocals) at Agricultural Research Station, Kampasagar. Further, through generation mean analysis, the nature and magnitude of non allelic interactions were investigated. Analysis of variance revealed the presence of sufficient variation in the experimental material. Through combining ability analysis, the parents, Akshyadhan, Basmati 370 and Sumathi were identified as the potential combiners for grain yield and prime component traits, panicle length, panicle weight, filled grains per panicle and 1000 grain weight. Whereas, Improved Pusa Basmati and Basmati 370 combined well for kernel characters including cooking quality traits. As such, these parents could be better utilized for breeding material generation. Among the crosses, Pusa 1121 x Sumathi, BPT 5204 x Basmati 370, Pusa 1121 x Basmati 370, BPT 5204 x NLR 145, Sumathi x Improved Pusa Basmati, RNR 2354 x Sumathi, BPT 5204 x Akshyadhan, RNR 2354 x Basmati 370, NLR 145 x Pusa 1121 and Akshyadhan x Pusa 1121 for different yield components; Pusa 1121 x Sumathi, BPT 5204 x RNR 2354 and BPT 5204 x Basmati 370, Pusa 1121 x Sumathi and Akshyadhan x Improved Pusa Basmati for kernel quality characters were identified as the best specific crosses in view of their high per se performance, sca effects and gca of their respective parents. Significant heterosis over mid and better parents was observed in many cross combinations. The crosses, Akshyadhan x Pusa 1121, Akshyadhan x Sumathi, NLR 145 x Pusa 1121 and RNR 2354 x Improved Pusa Basmati exhibited highly significant heterosis and heterobeltiosis for yield and component characters besides earliness. The other promising crosses for both yield components and quality traits were NLR 145 x Basmati 370, Sumathi x Improved Pusa Basmati, Pusa 1121 x Sumathi and Akshyadhan x Improved Pusa Basmati. High heterosis in F1 generation was accompanied by high inbreeding depression in F2 generation for the prime yield component, grains per panicle, whereas, the inbreeding depression was very low for panicle weight and 1000 grain weight. Hence, direct selection for yield improvement through these two characters would be highly beneficial. Considering this point, Akshyadhan x Pusa 1121 for yield potential and BPT 5204 x RNR 2354 and Akshyadhan x Basmati 370 for good cooking qualities with aroma were recommended for straight selection. Generation mean analysis was performed to detect the epistasis and estimate 5 components (m, d, h, i and l) as per 5 parameter model. The C and D scaling tests and the joint scaling test (3 parameter model) confirmed that the additive dominance model was inadequate to explain the inheritance of these characters. Based on the magnitudes of fixable genetic variation (‘d’ & ‘i’ types) and per se, pedigree selection in segregating generations with respect to crosses, BPT 5204 x Sumathi, RNR 2354 x Basmati 370 and Sumathi x Improved Pusa Basmati (for yield and quality) and BPT 5204 x Akshyadhan, Akshyadhan x NLR 145, Akshyadhan x Pusa 1121 (for grain yield) and BPT 5204 x Pusa 1121, Improved Pusa Basmati x Basmati 370 (for quality alone) was recommended. In F2 and F3 generations, among the yield characters, highest PCV and GCV values were recorded for no. of filled grains/panicle followed by grain yield and panicle weight indicating greater scope of obtaining high selection response for these traits. High heritability (F2 and F3) along with medium to high genetic advance was noticed for the trait, 1000 grain weight and most of the kernel traits, which facilitates direct selection in segregating populations for development of pure lines with good yield potential and quality. Eleven crosses with high per se performance, heterosis coupled with less inbreeding depression were carefully choosen and genetic parameters viz., GCV, PCV, h2 (bs) and GA) were estimated to suggest suitable breeding techniques on cross wise basis. Based on these results, direct selection for yield improvement in two crosses viz., Sumathi x Basmati 370 and Akshyadhan x NLR 145 and for quality improvement in five crosses viz., NLR 145 x Pusa 1121, Pusa 1121x Sumathi, Pusa 1121x Improved Pusa Basmati, Sumathi x Improved Pusa Basmati and Improved Pusa Basmati x Basmati 370 was considered as highly feasible and recommended. A critical analysis of both character association and path analysis in F1, F2 and F3 indicated that, among the yield components investigated, panicle weight and no. of filled grains/panicle are very important, as the correlation coefficients as well as the direct effects were high irrespective of the generation. The results of the present study revealed that the nature and magnitude of gene effects differ depending on the cross and character under consideration. Hence, apart from direct selection, the other procedures like recurrent selection or biparental mating in early segregating generations to poolup desired genes is also recommended depending on the cross combination. Taking into consideration the whole genetic analysis through the present investigation, pedigree selection in the cross combinations, Akshyadhan x Pusa 1121, NLR 145 x Pusa 1121 and BPT 5204 x NLR 145 for grain yield and Akshyadhan x Improved Pusa Basmati and Pusa 1121 x Sumathi for kernel dimensions (length, L/B ratio) and BPT 5204 x RNR 2354 and Akshyadhan x Basmati 370 for cooking quality characters was considered as most feasible and rewarding. In respect of other superior crosses, instead of direct selection biparental mating in F2 generation followed by selection was recommended alternatively.enGENETIC, ANALYSIS, QUANTITATIVE, TRAITS, AROMATIC RICEThesis