COMBINING ABILITY AND MOLECULAR PROFILING OF PROMISING GENOTYPES OF FIELD PEA (Pisum sativum L.)
Loading...
Date
2023
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
RPCAU, Pusa
Abstract
The present investigation entitled “Combining ability and molecular profiling of promising genotypes of field pea (Pisum sativum L.)” was undertaken at Tirhut College of Agriculture, Dholi, Bihar state during Rabi, 2021-22 (Crossing programme) and Rabi, 2022-23 (Evaluation). The study was based to assess the general combining ability of parents, specific combining ability of hybrids, heritability, heterosis, yield and molecular profiling using SSR markers. In the present research work seven lines were mated with five testers in Line X Tester mating design resulting in 35 hybrids. The parents and their 35 hybrids along with check (RACHANA) were evaluated by planting in Randomized Block Design with three replications. The data was collected on days to 50 per cent flowering, plant height, number of primary branches, number of secondary branches, days to maturity, number of pods per plant, number of seeds per pod, pod length, 100 seed weight, grain yield per plant, harvest index, number of nodules per plant, nodules fresh weight and nodules dry weight.
Analysis of variance revealed highly significant differences among the genotypes for all the 14 characters studied. The analysis of variance for combining ability revealed significant differences due to parents, hybrids and various interactions indicating the existence of wider variability in the material studied and the results pertaining to the estimate of combining ability revealed that mean GCA variance were higher than the SCA variance for the characters, viz., number of secondary branches, plant height, number of pods per plant, grain yield per plant and number of nodules per plant which indicated preponderance of additive gene action in the inheritance of these traits. Therefore, selection for these traits in early generations would be effective for developing the varieties in pea breeding programme. This was further supported by high magnitude of σ2gca/σ2sca ratio was more than unity suggesting the preponderance of additive variance in expression of these traits. Whereas SCA variance was relatively greater in magnitude than GCA variance for days to 50% flowering, number of primary branches, number of seeds per pod, 100 seed weight, pod length, nodules fresh weight and nodules dry weight indicating that these traits were predominantly under the control of non-additive gene action which can be further used for heterosis breeding.
High heritability coupled with high genetic advance estimates was recorded for number of secondary branches, plant height, pod length, number of seeds per pod, number of pods per plant, 100 seed weight, grain yield per plant, harvest index, nodules fresh weight and nodules dry weight indicating the role of additive gene action and selection for these traits is reliable. High heritability and moderate genetic advance were recorded for number of primary branches and number of nodules per plant indicating the presence of both additive and non-additive gene action. While high level of heritability and low genetic advance for days to 50% flowering and days to maturity indicating the role of non- additive genes in the inheritance of these traits and improvement of these traits through mere selection is not useful therefore breeder should go for heterosis breeding or recurrent selection for improvement of these characters.
General combining ability effects of the parents revealed that lines RFPG 111, TRCP8 and HUPT 1810 were found to be good combiners for traits like days to 50% flowering, days to maturity, number of seeds per pod, number of pods per plant, number of secondary branches, 100 seed weight, harvest index, nodules fresh weight and nodules dry weight. Whereas among the testers, IFP 18-7 has found to be good general combiner for the traits number of seeds per pod, number of pods per plant, harvest index, number of nodules per plant, nodules fresh weight and nodules dry weight. Thus, the parents RFPG 111, TRCP 8, HUPT 1810 and IPF 18-7 which has recorded significant positive GCA effects for grain yield per plant and its related traits can be utilized in the development of superior hybrids. Within the hybrids, IPFD 19-9 X HFP 1545, TRCP 8 X HFP 1545, DDR 23 X IPF 18-7 and RFPG 111 X IPF 18-7 exhibited positive SCA effects for grain yield per plant. Hence, considered as good specific combiners and could be recommended for heterosis breeding.
Estimates of heterobeltiosis and standard heterosis varied in a preferable direction among the crosses, and some of them proved to be the most effective in their respective contexts. The simultaneous manifestation of heterosis for yield component characteristics is the main cause of heterosis for grain yield per plant. The hybrids VL 42 X IPF 18-7, TRCP 8 X HFP 1545, RFPG111 X PANT P 462, DDR 23 X IPF 18-7, RFPG 111 X IPF 18-7 and IPFD 19-9 X IPF 18-7 had recorded highest heterobeltiosis along with per se, standard heterosis with respect to the check and high grain yield per plant.
By considering all the factors, the most promising parents identified were TRCP 8 and IPF 18-7 based on high grain yield per plant, high GCA and its yield components. Whereas the hybrid RFPG 111 X IPF 18-7 was found to be best specific combiner due to factors like duration, per se performance, SCA effect, standard heterosis over check RACHANA, heterobeltiosis, grain yield, number of primary branches, number of pods per plant, harvest index, nodules fresh weight and nodules dry weight. After being critically assessed for their superiority and stability across many places over years, these hybrids might be used commercially.
A set of 16 SSR markers were used for assessing the diversity at molecular level in 12 parental genotypes. The markers were found to be distinct and scorable for the genotypes evaluated. Altogether 53 allelic variants were detected among 12 pea genotypes with an average of 3.3 alleles per locus. A total of 33 shared and 20 unique allelic variants were generated in the form of amplified products by using 16 primer pairs. The PIC values revealing allelic diversity and frequency among the pea genotypes varied from 0.82 to 0.27.
The polymorphic primers were run among all the parents of which four primers viz., PEA 028, PEA 081, PEA 091 and PEA 126 had polymorphism. All the four primers have shown the presence of heterozygous band confirming the hybridity of these crosses. The dendrogram representation of the 12 parental genotypes revealed that the cluster IA had maximum number of genotypes. The magnitude of dice similarity coefficient among the parents RFPG 111 and TRCP 8 and TRCP 8 and HUPT 1810 had shown minimum value indicating the diversity among the parents.