2018 ASHS Annual Conference

Marker-assisted backcrossing contributes significantly to get over the main drawbacks in the ancient manual breeding approach (conventional) and speeds up the genome recovery of the recurrent parent (RPG). Recently, chilli output in Malaysia plunged due to El Nino, leading to the shortage of supply. El Nino is a complex series of climatic changes that occurs irregularly and affects sea surface temperature in most tropics and subtropics. To increase production there is the need to improve/produce varieties having high yielding potentials as well as tolerance against high temperature that will be suitable for lowland cultivation.

The strategy was adapted to introgress Hsp genes from AVPP0702, donor, into the genetic profile of Kulai variety, recipient. Parents were crossed and backcrossed to generate F₁ hybrids and backcross generations. Sixty-eight markers appeared to be polymorphic between the parents and used to assess the backcross generations; BC₁F₁, BC₂F₁, BC₃F₁ and BC₃F₂. The average RPG percentage of the recurrent parent in BC₁F₁, BC₂F₁, BC₃F₁ and BC₃F₂ was found to be 81, 90, 95 and 97% respectively. To confirm the presence of Hsp genes, gene expression analysis was carried out for the selected plants with high recovery of the recurrent parent. Polymorphic Hsp-linked markers were identified between the parents, F₁, BC₁F₁, BC₂F₁, BC₃F₁ and BC₃F₂ and their Hsp expression levels (up-regulated with more than 4-fold increase) were similar with the donor parent indicating successful introgression of the target gene. Furthermore, selected BC₃F₂ plants were evaluated for agro morphological performance which was found to be similar with the recurrent parent.

Improved high-yielding heat tolerant chilli lines showed tolerance to high temperature as well as did not express any negative effect on agronomic traits in comparison with Kulai variety. It is expected that the newly developed heat tolerant lines would increase chilli production to enhance and sustain future livelihoods and food security in Malaysia and other heat prone areas vis-a-vis climate change.