Heterosis in Vegetable Crops

To meet the challenge of providing food and nutritional security for an ever-increasing human population, particularly in the Indian sub-continent, commercial and strategic exploitation of heterosis is of vital importance. Hybrid technology is one of the potential and pragmatic options to meet the huge food, fodder and fiber requirements that are the need of hour. The effective use of hybrid technology has also accelerated the development and expansion of seed-industry worldwide. Heterosis or hybrid vigour, a phenomenon where hybrid progeny has superior performance compared to its parental inbred lines, has been the basis of much of the yield improvements in crop plants including vegetables during last century. Gene interactions between the two genomes such as dominance, over-dominance, and epistasis have been suggested to explain the increased biomass and yield. Large scale hybrid seed production sometimes remains handicapped because of high labour cost, unavailability of trained labour at crucial times, bad weather conditions like continuous rains etc.

The phenomenon like male sterility and self-incompatibility help to overcome these problems.These are of special interest for plant breeders to produce more efficient and economic hybrid seeds. Till date, 151 vegetable hybrids have been recommended for cultivation in different parts of the country based on multi location testing. Heterosis has contributed to increased crop yield for over 100 years, still the molecular mechanisms of heterosis is not understood. Availability of novel genetic and genomic tools,that allow for the integrated study of the complex interactions between genome organization and expression might contribute to a better understanding of heterosis.