Defining the genetic basis of Phytophthora capsici resistance
In an effort to define the inheritance and combine genetic factors controlling resistance to Phytophthora capsici in pepper, the SBC is leveraging technology developed to screen 31,000 genes simultaneously (Hill et al., 2013). A high-density genetic map was generated from 63 RILs derived from Criollos de Morelos (CM334) and Early Jalapeno. The population has been screened with 20 isolates of P. capsici from Mexico, US and Peru. Virulence of isolates was not correlated with species or region of origin. Dense genetic maps have revealed high quality candidate genes in major QTL for resistance. This research has been utilized to recruit grade-school and undergraduate students into plant sciences (see Education). This project is funded by the USDA National Institute of Food and Agriculture and the Department of Plant Sciences, UC Davis.Determining the basis of haploid induction
Doubled-haploid plants provide simpler genetics and can significantly enhance breeding programs. They are pure breeding and can be produced in a single generation using various methodologies, including culture of pollen grains (microspores). In pepper, only certain lineages are amenable to this technology. The SBC partnered with Rijk Zwaan to study the genetic bases of embryogenesis and regeneration of plants from microspores in pepper. The SBC is currently screening a large RIL population to correlate genotype with phenotypes, with the goal of identifying genes regulating embryogenesis and regeneration that may confer genotype specificity to anther culture in pepper.
Sequencing the pepper genome
In 2013, the SBC continued its collaboration with Doil Choi, Seoul National University. The pepper genome was assembled and annotated, providing insight into the regulation of capsaicin production in pepper and genomic comparisons with tomato for disease resistance and fruit ripening. This work was co-funded by a consortium with Seoul National University, Enza Zaden, HortiGenetics Research, Monsanto, Nunhems, Rijk Zwaan, Syngenta, Sakata Seed America, Semillas Fito and Takii.
Engineering tolerance to drought in pepper
The SBC is partnering with Eduardo Blumwald
(UC Davis) to extend to peppers a technology proven to confer drought tolerance in peanut, rice and tobacco (Reguera et al. 2012). Expressing a gene that results in the production of the plant hormone cytokinin in response to stress has protected yield under water stress in several crops. The SBC created the transgenic plants and is in the process of evaluating efficacy of this gene in pepper. This research is supported by a fellowship to Jaser Aljaser
by the Kuwait government.