Hurdles in developing hybrids: experience from a decade of hybridization in litchi

Efforts to enrich the varietal wealth in litchi with desired cultivars have been attempted. At ICAR-NRCL hybridization efforts have been emphasized for the past decades. The observed characteristic features and constraints encountered during the period were identified and systematic observations were taken. Studies show that the low genetic variability, small window of flowering period and stigma receptivity, small flower size, panicle injury, high flower and fruit drop, low seed germination and survivability are the prime hurdle that needs to be addressed. On average, the flowering period reported is 10–14 days which is even shorter during periods of increasing weather temperature. Across cultivars, the effective pollination period is very narrow and coincidence of stigma receptivity among cultivars was observed making it very challenging to attempt a maximum number of crosses within a short period. It was also observed that large numbers of small-sized and delicate flowers are produced in a panicle which injure the panicles during thinning and emasculation. Less than 3% of pollinated flowers were observed to attain fruit set which also registered low fruit retention during subsequent fruit development. The attack of seed borer at both the early and mature stages of fruit growth was noted which rendered the seeds non-viable. Parent incompatibility and very low success rate of hybrid seedling establishment were also observed especially in crosses involving small seeded parents like ‘Bedana’. Here we present findings from a decade of experimentation on hybridization in litchi and document hurdles that come in the way of developing hybrids in litchi. Such information will be crucial for devising strategies for an effective litchi breeding programme.