HETEROSIS AND COMBINING ABILITY EFFECTS FOR SOME TRAITS OF PEA (Pisum sativum L.)

Abstract

This study was carried out at the college of Agriculture field, University of Duhok, during 2013-2014 growing season. It involved half diallel crosses among five genotypes of pea.The seeds of genotypes (parents and F1 hybrids) were grown according to Randomized Complete Block Design with three replications, to estimate general combining ability effects of the parents and specific combining ability effects of hybrids, heterosis as deviation from mid and better parents for the following characters, Days to 50% flowering, plant-hieght (cm), numbers of branches plant-1, number of pods plant-1, pods weight plant-1 (g), number of seeds plant-1, numbers of seeds pod-1,100 seed weight (g), seed yield plant-1 (g), dry seed yield plant-1 (g), protein percentage and total chlorophyll percentage.The data was statistically analyzed according to Griffing (1956b) method 2 (fixed model).The results indicated that Parent (Petit provencal) showed the best general combination in the desirable direction for no. of pods plant-1, no. of seeds plant-1, no. of seeds pod-1, seed yield plant-1, dry seed yield plant-1 and total chlorophyll. Hybrid (Thomas laxton x Petit provencal) exhibited significant specific combining ability effect in a desirable direction for plant height, no. of branches plant-1, pods weight plant-1, no. of pods plant-1, no. of seeds plant-1, seed yield plant-1 and dry seed yield plant-1. The hybrids (Avola x Petit provencal) and (Thomas laxton x Petit provencal) gave the best heterosis in desirable direction measured as a deviation of F1 from mid-parents for days to 50% flowering, pods weight plant-1, no. of pods plant-1, no. of seeds plant-1, no. of seeds pod-1, seed yield plant-1, dry seed yield plant-1, total chlorophyll and also the same hybrids showed a high heterobeltiosis values for (5) characters for each hybrid which include (pods weight plant-1, no.of pods plant-1, no. of seeds plant-1, seed yield plant-1 and dry seed yield plant-1). Keyword: general and specific combining ability, heterosis in pea.

Relationship of Quantitative Traits in Different Morphological Characters of Pea (Pisum Sativum L.)

“…El -Dakkak [13] found negative heterosis (-16.82%) based on the tallest parent for this trait. Significant positive heterosis based on an early parent was observed in all garden pea crosses for days to the flowering trait [14], while, Askander and Osman [15] found negative heterosis in some crosses and positive heterosis values in the others. The data from these studies provide an opportunity to combine appropriate traits in one genotype and increase the efficiency of the breeding activity [16].…”