Plant Genomics

Biography

Biography: Guangyuan Lu

Abstract

The production of     oilseed rape    , a globally important oil    crop   , is tremendously limited by d rought 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 st ress 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 wa  ter content was identified as a good indicator for early screening of drou  ght 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 susceptibili ty index of yield. Phenotypic corre  lation 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 a s 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 d rought-prone environments in the Northwest of China. To facilitate the    breeding    of drought tolerance with the aid of molecular markers, we conduct exp eriment-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.