不同处理对沙生针茅种子萌发的影响

Effects of various treatments on seed germination of Stipa glareosa

沙生针茅是重要的荒漠植物,研究其种子萌发特性及其对主要影响因子的响应对于认识其生存适应性以及荒漠植被恢复具有重要意义。鉴于沙生针茅种子常处休眠状态、不易萌发,而现有研究尚未充分揭示各种因素和处理对沙生针茅种子萌发的影响,本论文报道了不同因素、不同处理对沙生针茅种子萌发的影响。结果表明:(1)60℃蒸馏水浸泡种子24 h,种子吸水率、发芽率、发芽势分别达到26%、38%和32%;(2)-20/20℃变温处理96 h,发芽率、发芽势分别达到48%和46%;(3)切除绝大部分胚乳(3/4)后,种子发芽率、发芽势分别可达到58%和54%;(4)用80 mg·L^(-1)赤霉素(GA3)水溶液浸泡种子24 h,发芽率、发芽势分别达到54%和48%;(5)用聚乙二醇(PEG-6000)处理,随浓度增加,种子发芽率、发芽势、发芽指数均呈下降趋势,种子萌发水分胁迫的临界值和极限值分别为15.9%和26.3%;(6)盐胁迫处理下,种子发芽率、发芽势、发芽指数均随盐碱浓度增加呈下降趋势,其中Na2CO3处理下的种子萌发率下降幅度明显大于Na Cl,表明碱性盐胁迫对沙生针茅种子萌发的抑制作用大于中性盐胁迫;(7)采用综合处理方法,种子发芽率、发芽势分别达到78%和76%。

This paper reports seed germination rate and seed germination potential of Stipa glareosa under the treatments of 60 ℃ water soaking, -20/20 ℃ alternating temperature, soa- king with 80 mg · L-1 gibberellic acid solution （GA3 ）, drought stress induced by polyethylene glycol （PEG-6000） , salt stress induced by NaECO3 or NaC1 solution, the combination treatment of-20/20 ℃ alternating temperature and soaking with 80 mg · L-1 gibberellic acid solution （GA3）. The results showed that： （1） Water-absorption rate, germination rate and germination potential rate of the seeds soaked in 60 ℃ distilled water for 24 h were 26%, 38% and 32%, re- spectively; （2） The germination rate and germination potential of seeds treated at -20/20 ℃ al- ternating temperature for 96 h were 48% and 46%, respectively ; （3） After removing of 3/4 of the endosperm, the germination rate, germination potential reached 58% and 54%, respectively ; （4） The seed germination rate and germination potential were 54% and 48% under the 24 h long soaking treatment with 80 mg · L-1 GA3 solution. （5） Under the treatment of PEG-6000, the seed germination rate, germination potential, and seed vigor index decreased with the increase of PEG-6000 concentration, and the threshold and maximum PEG-6000 concentrations for germina- tion were 15.9% and 26.3%, respectively. （6） Under the salt stress treatment, the seed germi- nation rate. ermination notential, and seed viar index dee, ranged with the increase afnlinitvThe decline in seed germination rate under the salt stress treatment of Na2COs solution was signi- ficantly greater than that of NaC1 solution, showing that the inhibition of alkaline salt stress to seed germination is greater than that of neutral salt stress. （7） Under the combination treatment, the seed germination rate and germination potential were 78% and 76%, respectively.