无芒隐子草花序不同部位种子萌发期光照需求及抗旱性综合评价

以无芒隐子草(Cleistogenes songorica)花序不同部位的种子为材料,采用聚乙二醇(PEG-6000)模拟不同水势(0.0,-0.2,-0.4,-0.6,-0.8 MPa)研究种子萌发期光照需求并进行抗旱性综合评价。结果表明:花序各部位种子的发芽率、发芽势、发芽指数以及活力指数等指标随着渗透势的降低而减小。适度的干旱胁迫促进胚根生长,然而干旱胁迫对胚芽生长则始终起到抑制作用。无芒隐子草花序各部位种子在萌发过程中均需要光照条件,在黑暗环境下其种子发芽率、发芽势等指标均显著下降,胚根长度与胚芽长度亦显著低于光照条件。用模糊数学隶属法综合评价各部位种子的抗旱性,结果表明其抗旱性自高至低依次为:中部下部上部顶部,鞘藏小穗中种子的抗旱性远高于顶穗中的种子,在无芒隐子草的建植中应该优先考虑。

Light Requirement and Evaluation of Drought Resistance of Cleistogenes songorica Seeds from Different Inflorescence Positions at Germination Stage

The performance of Cleistogenes songorica seed germination and early seedling growth of the seeds harvested from different inflorescence positions were evaluated under different water potential (0.0,-0.2,-0.4,-0.6,-0.8 MPa) and light regimes.The Fuzzy Mathematics Based Comprehensive Evaluation method was used to investigate the drought tolerance of the seed harvested from different inflorescence positions.The results showed that germination percentage, germination energy, germination index and vigor index reduced significantly with the decline of osmotic pressures.Moderate osmotic stress significantly increased the radicle length, while under the tested osmotic stress treatmetns plumule length was reduced significantly.Seed germination and seedling growth were significantly decreased in darkness compare with that of under light condition.The results of analysis of drought tolerance using Fuzzy Mathematics Based Comprehensive Evaluation suggested that seeds from four positions in seed germination ranked as:Middle＞ Bottom＞ Upper＞ Top spike.Seeds from internodes spike should be highly recommend ensuring the successful establishment of C.songorica.