Predicting the frequency of transgressive RILs and minimum population size required for their recovery in horse gram (Macrotyloma uniflorum (Lam.) Verdc)

Abstract

Early elimination of poor crosses based on an objective criterion allows increased allocation of resources only to a few promising crosses for identifying superior recombinant inbred lines (RILs) for use as pure-line cultivars in self-pollinated crops. Early generation (F2:3) prediction of frequency of superior RILs that could be derived from advanced generations of crosses is one such criterion. We predicted the frequency of transgressive RILs from two horse gram crosses (namely HPKM 320 × CRIDA18-R and IC 361290 × Palem 1) for primary branches per plant, pods per plant, pod weight per plant and grain weight per plant based on mid parental value, additive genetic effects and additive genetic variance estimated from trait means of parents, and their F2 and F2:3 generations. The predicted frequency of RILs that transgressed better parent/two checks varied with the cross and the trait within a cross. The frequencies of transgressive RILs predicted from IC 361290 × Palem 1 were higher than those predicted from HPKM 320 × CRIDA 18-R for three of the four traits. As expected, the minimum population size required to recover the transgressive RILs predicted from IC 361290 × Palem 1 was relatively smaller than that from IC 361290 × Palem 1. Increased allocation of resources for handling segregating populations derived from IC 361290 × Palem 1 is expected to result in superior RILs for use as cultivars. We believe that the objective criterion used in our study is handy in identifying superior RILs in early segregating populations derived from a few promising crosses.

Predicting, Validation of Frequency of Transgressive Recombinant Inbred Lines and Minimum Population Size Required to Recover them in Groundnut (Arachis hypogaea L.)

“…The results suggest the credibility of this approach in predicting the frequency of transgressive RILs. Similar results were reported by several researchers such as Carneiro et al [13] in common bean, Chahota et al [1] in lentil, Shivakumar et al [11] in dolichos bean and Chandana et al [12] in horse gram.…”

“…The parents should be genetically diverse yet phenotypically similar. Empirical results in other grain legumes such as lentil [1], dolichos bean [11] and horse gram [12] also suggested the robustness of the prediction method used in our study in order to assess the breeding potential of the cross.…”

Predicting the Frequency of Transgressive RILs and Minimum Population Size Required to Recover Them in Dolichos Bean [Lablab purpureus (L.) Sweet]

“…This is possible when the parents are genetically diverse, though phenotypically similar. Empirical results in other grain legumes such as lentil (Chahota et al, 2007), dolichos bean (Shivakumar et al, 2016) and horse gram (Chandana et al, 2022) provide adequate evidence for the robust reliability of the prediction approach used in the present study to assess breeding potential of crosses.…”

Organization of Genetic Variability and Trait-specific Accessions in a Diverse Set of Horse Gram [Macrotyloma uniflorum (Lam.) Verdc.] Germplasm

“…It is one of the good sources of protein to a large number of people, especially to those depending on vegetarian diet for source of energy (Morris, 2008). It is predominantly grown in marginal soils in rainfed ecosystems by resource-poor farmers (Chandana et al 2022). The productivity of horse gram in farmers' fields is rather low compared to that of other legumes such as soybean, cowpea, green gram, black gram, pigeon pea, etc.…”

“…The productivity of horse gram in farmers' fields is rather low compared to that of other legumes such as soybean, cowpea, green gram, black gram, pigeon pea, etc. Limited efforts to breed horse gram compared to other legumes (among others) is attributed to low horse gram productivity (Chandana et al 2022). Further, breeding populations are most often developed by crossing elite parents in horse gram as well, as is true in other selfpollinated crops.…”