Embryo rescue and plant regeneration in vitro of selfed chickpea (Cicer arietinum L.) and its wild annual relatives

Abstract

The main constraint to the transfer of desired traits into cultivated chickpea from wild Cicer relatives is the presence of post-zygotic barriers which result in abortion of the immature embryo following interspecific hybridisation. Rescue of hybrid embryos in vitro and regeneration of hybrid plantlets could allow chickpea breeders to transfer desirable traits from wild relatives of chickpea. The development of embryo rescue techniques using selfed chickpea and selfed wild relatives is being used as a first step to protocols for wide hybrids. Optical microscopy studies of embryogenesis, in both selfs and hybrids, identified deleterious changes in the fertilised hybrid seed as early as 2-4 days after pollination in some crosses. These observations suggest that the appropriate time to rescue chickpea  C. bijugum hybrids is at the early globular stage of embryogenesis (2-7 days old), which requires the development of a complex tissue culture medium. In contrast hybrids between chickpea  C. pinnatifidum abort later (up to 15-20 days old) at the heartshaped or torpedo stages, and are easier to rescue in vitro. Genotype also plays a significant role in the ability of immature selfed ovules to germinate in vitro. In this paper we report on the optimisation of protocols for rescueing immature embryos using selfed chickpea and its wild relatives in ovule, and subsequently to regenerate plantlets.

Factors affecting seed set in the crosses between Dendranthema grandiflorum (Ramat.) Kitamura and its wild species

“…Embryo abortion is another important factor related to fecundity (Mont et al 1993;Singh 1998;Mallikarjuna and Saxena 2002;Datson et al 2006). For instance, Clarke et al (2006) reported that the main constraint of the transfer of desired traits into cultivated chickpea from wild Cicer relatives was the presence of post-zygotic barrier, i.e., abortion of the immature embryos. Similarly, Ndoutoumou et al (2007) found that embryo abortion after fertilization was the main factor causing failure of the cross between Phaseolus vulgaris and P. coccineus.…”

Legume Crops Phylogeny and Genetic Diversity for Science and Breeding

“…Successful hybridizations between the cultivated chickpea and C. reticulatum or C. echinospermum and their reciprocals have been reported (Ladizinsky and Adler, 1976ab;Jaiswal and Singh, 1986;Singh and Ocampo, 1993;Croser et al, 2003;Ahmad and Slinkard, 2004;Singh et al, 2005;Clarke et al, 2006;Knights et al, 2008;Malikarjuna et al, 2011;Thompson et al, 2012). Although some of the accessions of C. bijugum, C. judaicum and C. pinnatifidum used as pollen donors were crossed with the cultivated chickpea, hybrids were available via embryo rescue techniques (Ahmad and Slinkard, 2004).…”

Fruit, seed and embryo development of different cassava (Manihot esculenta Crantz) genotypes and embryo rescue

“…Rescuing and culturing younger embryos when they are not readily visible may require the inclusion of other tissue such as embryo sac and even part of the ovary. Likewise, parental genetic, phenological and physiological differences can also contribute to variations in the in vitro responses of rescued embryos (Clarke et al, 2006).…”