Guangyuan Lu
Chinese Academy of Agricultural Sciences, China
Title: Breeding of Drought Tolerant Canola: from Laborotary to the Field
Biography
Biography: Guangyuan Lu
Abstract
The production of oilseed rape, a globally important oil crop, is tremendously limited by drought stress. To cope with this issue, the breeding of new cultivars with improved ability to drought stress is of great interest. To this aim, we carried out experiment-1 to establish selection criteria for drought tolerance at differant developing stages. The impact of water deficit imposed at the germination stage or the reproductive stage on biological traits of 37 semi-winter rapeseed cultivars were first analysed. The results showed that osmotic stress induced by 14% polyethylene glycol (PEG-6000) had a substantial impact on seed germination and caused a significant reduction in plant growth and seed vigor. Relative water content was identified as a good indicator for early screening of drought tolerance. At the reproductive stage, seed yield, 1000-seed weight, height of the first branch, plant height, and number of pods per plant were all markedly reduced under the exceptionally long (>100 d) and severe drought condition (a total of 162 mm precipitation during rapeseed life cycle, 52% reduced). Two of the top three tolerant genotypes at the germination stage were also shown to be tolerant based on drought susceptibility index of yield. Phenotypic correlation and path analysis were employed to rank the relative importance of other agronomic traits with regard to seed yield. The important contributors to seed yield under drought conditions, in descending order, were as follows: 1000-seed weight, days to maturity, number of pods per plant, and plant height. By taking this concept in mind, we have recently bred a new drought-tolerant cultivar (YG85) that can be grown in the drought-prone environments in the Northwest of China. To facilitate the breeding of drought tolerance with the aid of molecular markers, we conduct experiment-2 with a panel of 101 lines, which had previously been analyzed by RNA-Seq. The evaluation of drought tolerance at seedling stage resulted in the identification of 7 drought tolerant lines that could be incorporated into breeding programme. The ongoing genome-wide Associative Transcriptomics analysis is expected to bring about the discover of some candidate genes underlining drought tolerance and the development of functional markers.