Polyethylene glycol induced drought stress strongly influences seed germination, root morphology and cytoplasm of different kenaf genotypes

摘要

Plants are sessile and therefore continuously confronted to drought stress. Therefore, a better understanding of different kenaf genotypes is essential. The objective of this study was to assess seed germination, root morphology and cytoplasmic effects of four types of kenaf cytoplasms i.e., C1, C2, C3, C4 under different concentration of polyethylene glycol (PEG). Results showed that seed germination was increased under 10% PEG treatment compared with control and 20% PEG treatment. Among the genotypes, the hybrids C2/992, C3/992, C4/992 resulted in better germination compared with P3B and FH992. The C2 cytoplasm had the most positive cytoplasmic effects on seed vigor at germination stage. Root growth was significantly inhibited under 10% PEG and 20% PEG at seedling stage. C3/992, P3A, and P3B had improved root growth compared with other treatments at seedling stage. Under 20% PEG conditions, Cl, C2, C3, and C4 cytoplasms had inhibitory effect on root growth traits except C3 cytoplasm had a positive effect on root growth. Correlation analysis showed that hundred-grain weight (HGW) was significantly correlated to seed germination performance (P 0.01) and root dry weight (P 0.05) under 20% PEG conditions. In particular, the CMS line P3A was the most beneficial in terms of higher germination rate and better root morphological characteristics. This indicating that P3A had the potential to withstand under drought conditions and could be used for drought resistant breeding of three-line system of kenaf crop with heavy hundred p-grain weight of restorer line.