Application of somatic hybridization for the improvement of horticultural crops

A.K Singh,Sudhakar Pandey,Sanjeev Kumar,N.K Mishra

doi:10.19071/jhcbt.2015.v1.2897

Abstract

<p>Somatic hybridization (SH) using protoplast fusion is a promising tool to produce symmetrical and asymmetrical polyploidy somatic hybrids in many agricultural crops. The technique of SH could facilitate conventional breeding by providing of novel lines so as to use them as elite breeding materials in conventional crosses for both scion and rootstock improvement. Further, SH can overcome those problems associated with sexual hybridization viz., sexual incompatibility, nucellar embryogenesis, and male/female sterility. Successful exploitation of SH in horticultural crops mainly comes from transfer of resistance genes for biotic and abiotic stresses from related species in several horticultural crops, <em>viz</em>., citrus, potato, brinjal, tomato, mango, avocado, banana, strawberry, pear, cherry etc. Unlike transgenic technology, SH is not affected by legal formalities and able to transfer uncloned multiple genes. However, certain boundaries and limitations of SH restricts its use over sexual hybridization but, envisage of new genomic technologies providing better insight into the plant genomes will increase the potentiality of SH in betterment of agriculture.</p>

Highlights

Somatic hybridization (SH) via protoplast fusion is an important tool for the production of interspecific and intergeneric hybrids
The technique of SH involves the fusing protoplasts of two different genomes followed by the selection of desired somatic hybrid cells and subsequent regeneration of hybrid plant
SH has been used for salt tolerance, quality improvement, transfer of cytoplasmic male sterility (CMS), seedless triploids and rootstock improvement (Wang et al, 2013)

Summary

INTRODUCTION

Somatic hybridization (SH) via protoplast fusion is an important tool for the production of interspecific and intergeneric hybrids. Protoplast fusion effectively generates novel germplasm for elite breeding of conventional crosses and promotes crop improvement in existing cultivars Conventional breeding methods such as sexual hybridization cannot transfer some elite breeding traits (e.g., quality traits, disease resistance, and CMS) because of sexual reproductive barriers such as incompatibility, different bloom phases, male and/or female sterility, nucellar embryogenesis, and polyembryony (Aleza et al, 2010). This general rule was observed for crosses between S. melongena and S. aethiopicum, S. melongena and S. torvum, S. melongena and S. khasianum, and S. aethiopicum and S. violaceum (Tamura et al, 2002).The case of S. melongena and S. sisymbriifolium is an exception, in which SH produced a viable, albeit sterile, hybrid, whereas, sexual hybridization was not successful (Collonnier et al, 2003) Despite progress in this area, no eggplant cultivar, to date, has been produced via interspecific protoplast fusion. Isozymes, random amplified polymorphic DNAs and inter simple sequence repeat markers are used to confirm the origin of dihaploid plants derived from S. melongena-S. aethiopicum somatic hybrids carrying Fusarium wilt resistance (from the S. aethiopicum parent) (Rizza et al, 2002)

CITRUS SPECIES

USE OF SH IN OTHER IMPORTANT FRUIT CROPS

FUTURE PROSPECTS