Attempts to overcome postfertilization barrier in interspecific crosses of the genus Lens

Abstract

Wild relatives are a potential source of genetic diversity to lentil {Lens culinaris Medik). The objective of this research was to obtain viable interspecific hybrids between the domesticated lentil and its wild relatives.The paper details the results of a number of interspecific crosses among L. culinaris, L. orientalis, L. odemensis, L. ervoides and L. nigricans. Viable hybrids were produced between L. culinaris x L. orientalis, L. culinaris x L. nigricans, L. culinaris x L. ervoides and between L. culinaris x L. odemensis. Further viable hybrids were obtained between L. culinaris and L. ervoides, which have the potential to be a 'bridge' in hybridization to L. culinaris for specific L. nicrigans lines which proved recalcitrant in L. culinaris x L. nigricans crosses. This is the first time that four wild species of lentils have been used successfully in hybridization with cultivated lentils, and viable hybrids produced. This paper also suggests that the artificial supplement of GA, hormone is needed after fertilization for the normal growth ofthe hybrid embryo, possibly as the natural GA, production is restricted with alien pollinations in cultivated lentils in both F, and backcross hybrids.

Lentil

“…tomentosus × L. lamottei (van Oss et al 1997 ), and L. culinaris ssp. odemensis × L. ervoides ) though viable hybrids have been reported between cultivated species and L. ervoides , L. odemensis , and L. nigricans with the use of GA3 (Ahmad et al 1995 ). reported a high correlation between crossing success and phenotypic similarity based on pollen morphology and in vitro pollen length together with pistil and style length, indicating good predictor of hybridization success between different species.…”

“…A two-step in vitro method of embryo-ovule rescue was developed to obtain successful distant hybrids by crossing the cultivated lentil with L. ervoides and L. nigricans (Cohen et al 1984 ). However, the same technique used by other workers could not produce the hybrids (Ahmad et al 1995 ;Gupta and Sharma 2005 ). Another study reported development of different protocol , which could be able to rescue the hybrid ovules 18 days after pollination.…”

“…In lentil, use of GA3 has resulted in development of viable F 1 s between cultivated species and L. ervoides , L. odemensis , and L. nigricans (Ahmad et al 1995 ).…”

“…Albino seedlings can also occur in the F 1 generation and thus prevent hybridization success (Ladizinsky and Abbo 1993 ). Another common problem is that hybrid embryos cease to grow about 7-14 days after pollination due to endosperm degeneration and thus need rescuing in order to obtain viable hybrids (Ladizinsky et al 1985 ;Ahmad et al 1995 ). Hence, L. culinaris × L. ervoides or L. culinaris × L. nigricans crosses need embryo rescue techniques in order to develop mature hybrid plants (Cohen et al 1984 ;Abbo and Ladizinsky 1991 ).…”

Breeding for resistance to lentil Ascochyta blight

“…The only wild species that can be intercrossed with cultivated lentil easily is L. orientalis, the progenitor of cultivated lentil (Ladizinsky 1979(Ladizinsky , 1993. A recent report showed that viable hybrids could be obtained from the crosses between the cultivated and four wild lentil species by applying gibberellic acid (GA 3 ) after pollination (Ahmad et al 1995). Upon improvement, this technique may lead to an efficient method to transfer useful resistance genes from these wild species into cultivated species.…”