The simple scaling test (Table 2) was found to be significant for all the cross combinations for days to 50% flowering, indicating the presence of non-allelic interaction,C and D scales were significant in HimMash-1xSirmour-2 and Palampur-93xKullu-4, while, HimMash-1xKullu-4 and HimMash-1xChamba-8 disclosed the significance of B, C and D scale. Palampur-93xChamba-8 had significance of A, C and D scale, whereas, Palampur-93xSirmour-2 revealed the significance of C scale. Thus, additive and dominance gene action was present in the crosses investigated.
Panigrahi et al., (2020) reported the prevalence of dominance and [l] gene effects in urdbean genotypes. Significant and opposite signs of [h] and [l] (Table 3) were present in all the crosses excluding Palampur-93xSirmour-2.
Kant and Srivastava (2012) divulged the presence of both complementary and duplicate epistasis for the trait in blackgram, whereas in current investigation only duplicate type of epistasis was detected, implying biparental mating followed by selection for trait enhancement.
The simple scaling test for days to 75% maturity was observed to be significant for all the crosses except Palampur-93xSirmour-2. In HimMash-1xSirmour-2 and Palampur-93xChamba-8, B type of scale was significant, HimMash-1xKullu-4 showed the prevalence of C and D scales, while in HimMash-1xChamba-8 all of the four scales were significant and in Palampur-93xKullu-4, A and C scales were significant. Thus, indicating the additive and dominance type of non-allelic interactions is involved in the inheritance of the trait.
Alam et al., (2014) anticipated the occurrence of additive, dominance and epistatic interactions.HimMash-1xSirmour-2, HimMash-1xKullu-4 and Palampur-93xChamba-8, showed the presence of duplicate gene action. Significant and positive [j] type of genic values in HimMash-1xSirmour-2, recommends the utilization of recurrent selection method for improvement of this trait. Contrarily, significant negative [i] type of genic values was prevalent in HimMash-1xKullu-4, which indicates allele dispersion in the parent and selection in subsequent generations.
Panigrahi et al., (2020) also reported the prevalence of duplicate gene action for days to 75% maturity which is parallel to the current investigation.
HimMash-1xSirmour-2 and Palampur-93xChamba-8 exhibited the predominance of A, B and C scales, indicating the prevalence of [i], [j] and [l] type of epistasis. HimMash-1xChamba-8 and Palampur-93xSirmour-2 demonstrated significant C scale, suggesting the preponderance of [l] type of epistasis. The assessments of gene effects in a six-parameter model demonstrated the existence of [d] and [h] genic effect; therefore selection should be delayed to later generation to obtained plants with desirable height. Similar but negative [i] and [l] gene interaction for the trait was observed by
Lenka et al., (2020), Panigrahi et al., (2020), while
Parsad et al., (2021) obtained positive [i] and [l] for plant height. This attribute was therefore regulated by additive and dominance gene effects.
None of the scale was observed to be significant for branches/plant in HimMash-1xSirmour-2 which showed the adequacy of additive-dominance model. Significance of scales B and C were observed for HimMash-1xKullu-4 and Palampur-93xKullu-4, while, A, B, C and D in Palampur-93xChamba-8, whereas, in HimMash-1xChamba-8 scale D was found to be significant. In Palampur-93xSirmour-2 scales C and D were significant. Therefore, above results implicated the prevalence of [i], [j] and [l] type of gene interaction for the transmission of the trait. Six-parameter model disclosed the prevalence of positive [h] gene effect in HimMash-1xKullu-4 and Palampur-93xKullu-4. In Palampur-93xSirmour-2 and Palampur-93xChamba-8 the preponderance of [h] gene effect and [i] inter-allelic interaction was observed, recommending hybridization and selection in later generations.The occurrence of duplicate gene action and positive [i] type interactions in Palampur-93xSirmour-2, thus, biparental mating proceeded by selection is recommended to increase the number of pods per plant.
Singh et al., (2007) and
Pathak et al., (2015)had also observed the prevalence of duplicate type epistasis and inter-allelic interactionsfor the trait.
For pod length A, B and C scales were significant in HimMash-1xKullu-4 and in Palampur-93×Chamba-8 A and C, while, in HimMash-1xChamba-8 [i] type gene interaction was prevalent as represented by significant D scale, confirmed the preponderance of [i], [j] and [l] type of non-allelic interactions.
Murugan (2005) also observed all three types of epistatic interaction.
Parsad et al., (2021) showed the involvement of [i] non-allelic interaction. Estimates of [d] and [i] genic effects demonstrated significant and positive values in HimMash-1xKullu-4, HimMash-1xChamba-8 and Palampur-93xKullu-4. This shows the complex nature of inheritance of this trait. Therefore, hybridization and selection in advanced generations is recommended when desirable recombinants become
available.Vaithiyalingam
et_al(2002) found additive and dominant effects for this characteristic.
Number of pods/plant is one of the most prominent morphological traits that make a significant contribution to seed yield/plant. In HimMash-1xSirmour-2 and HimMash-1xChamba-8 A and C scales, in HimMash-1xKullu-4 scales A, B and C, in Palampur-93xKullu-4 scales B and D and in Palampur-93xSirmour-2 scales B, C and D were significant, thus revealing [i], [j] and [l]non-allelic interactions were controlling the inheritance of the character. Palampur-93×Sirmour-2 showed the preponderance of [l] type of gene interaction, since scale C was significant. Six-parameter estimates disclosed the presence of significant positive values of [h] and significant negative values of [l] along with significant and positive [i] type of interaction incross combinations Palampur-93xKullu-4 and Palampur-93xChamba-8, indicating the presence of duplicate gene action. Thus, the investigation recommending the biparental mating followed by selection to effect the enhancement of the attribute. Results were in accordance with findings of
Pathak et al., (2015) for duplicate type of epistasis and
Ragul et al., (2021) for [i] gene action, supporting the above finding.
The number of seeds/pod is a major yield contributing attribute andits enhancement, together with the number of pods/plant, is the primary goal of plant breeding. The simple scaling test revealed the significant A, B and C scales in HimMash-1xSirmour-2 and HimMash-1xKullu-4 and significant B scale in Palampur-93×Sirmour-2, representing the presence of [i], [j] and [l] gene interaction. While, Palampur-93xKullu-4 and Palampur-93xChamba-8 possessed the [l] type of interaction as revealed by C scale. Significant [l] genic interaction was present in HimMash-1xSirmour-2 and HimMash-1xKullu-4. Significant and positive [h] gene effect was observed in cross HimMash-1xChamba-8. The preponderance of non-additive gene action as well as [l] effect were also previously recorded by
Murugan (2005) and
Parsad and Murugan (2021). As a result, selection for the character may be extended to advanced generations, when desirable recombinants become attainable,
(Inderjit et al., 2006; Patel et al., 2012).
The biological yield refers to the total dry matter accumulation of a plant system. It is a significant component and contributor to the harvest index. Increased harvest index indicates increased physiological potential to absorb photosynthates and transmit them towards organs with economic yield. The scaling tests revealed the significance of C and D scales in HimMash-1xKullu-4 and Palampur-93xChamba-8. In HimMash-1xSirmour-2, scales A and D were significant. Palampur-93xSirmour-2 showed significant C scale. Thus, confirmed the presence of [i], [j] and [l] type gene interaction. Six-parameter model for digenic control disclosed the presence of significant and positive [h] and [i] inter-allelic interaction in HimMash-1xKullu-4 and in Palampur-93xChamba-8. HimMash-1xSirmour-2 pertained significant positive [h] gene effect, implicating the biparental mating accompanied by selection.
Bindra (2017) also reported [h] and [i] genic interaction for the character.
The estimates of scaling tests disclosed the adequacy of additive-dominance model for the yield/plant in HimMash-1xSirmour-2, HimMash-1xKullu-4, HimMash-1xChamba-8 and Palampur-93xKullu-4 as these cross combinations had all the four scales non-significant. Palampur-93xSirmour-2 possessed all three types of interactions, since scales A and C were significant. Palampur-93xChamba-8 had significant C scale, demonstrating the [l] type of interaction.
Murugan et al., (2005) also reported the similar results as there were preponderance all the three types of epistatic interaction and [l] genic effect. Palampur-93xSirmour-2 had [l] type of inter-allelic interaction, so the breeding objective should be towards development of hybrids for commercial purpose.
Harvest index has the ability to dramatically enhance breeding for improved grain yield in any crop improvement strategy. The true objective of any breeding program is to improve yield, especially seed yield, where the crop’s economic product is seed. Thereby, in order to be designated as a commercial variety, a novel genotype/line must outperform the yield levels of a popularly established commercial variety while also containing useful genes for number of important traits. In current investigation, significance of scales A, B and C in Palampur-93xSirmour-2 and Palampur-93xChamba-8 revealed [i], [j] and [l] type of inter-allelic gene control was associated in the inheritance of the trait. Whereas, in HimMash-1xSirmour-2 and Palampur-93xKullu-4, scales C and D were significant, indicating the preponderance of [i] and [l] type of interaction. In Palampur-93xKullu-4 [l] type of gene interaction was present, since scale C was significant. Six-parameter model revealed the prevalence of duplicate epistasis, along with [i] type of interaction in HimMash-1xSirmour-2, thus recommending the hybridization and selection in advanced generations would be beneficial for the improvement of the trait.
Pathak (2015) and
Bindra (2017) also obtained the alike outcomes illustrating existence of duplicate epistasis for the trait.
HimMash-1xKullu-4, HimMash-1xChamba-8, Palampur- 93xSirmour-2, Palampur-93xKullu-4 and Palampur-93xChamba-8 exhibited [i], [j] and [l] gene interactions for 100-seed weight. Whereas, HimMash-1xSirmour-2, demonstrating the preponderance of [i] and [l] type of interaction. Duplicate type of epistasis in HimMash-1xChamba-8, Palampur-93xSirmour-2 and Palampur-93xKullu-4 revealed that bi-parental mating accompanied by selection in later segregants could lead to improvements.
Bindra et al., (2017), Singh et al., (2016),Sinhaet_al(2020) also found duplicate epistasis;
Parsad and Murugan (2021) got additive, dominance, epistatic interactions and duplicate dominant interaction for the trait;
Ragul et al., (2021) reported [d], [i] gene action and duplicate type of epistasis.