粗壮嵩草种子生物学及萌发特性研究

Kobresia robusta Maxim: Seed Biology and Germination Characteristics

为了揭示粗壮嵩草种子的休眠机理、萌发过程,解决种子的有性繁殖问题,在种子形态特征、解剖以及生活力观测的基础上,进一步将其种子用物理（热水浸种、机械处理、层积催芽及变温）及化学（浓H2SO4浸种、GA3处理）方法进行了萌发试验。结果表明：粗壮嵩草种子的生活力和千粒重分别为64%和4.63 g,而且由于种子被坚硬的种皮包裹导致种子萌发率较低。在常温（20～25℃）下,粗壮嵩草种子通过不同温度的热水浸种、机械和层积催芽等多种处理后均不发芽。然而,在25/5℃（12/12h）变温处理下,将粗壮嵩草种子种皮划破后,放置于98%的浓H2SO4中6 min,经300 mg/L赤霉素（GA3）浸泡48 h,在14天内粗壮嵩草种子的萌发率达到64%。但是,其余36%的粗壮嵩草种子的休眠仍未打破。以上研究结果说明,粗壮嵩草种子存在综合休眠的机制,并且种子种皮的机械限制可能是导致粗壮嵩草种子休眠的主要原因。

In order to reveal the dormancy mechanism and germination process and solve the problems ofsexual production of Kobresia robusta（Cyperaceae） seeds, the authors observed the seed morphology, anatomyand seed viability, and then carried out the germination test through physical（soaking in hot water, mechanicalprocess, laminated pregermination and temperature） and chemical（soaking in concentrated sulfuric acid, GA3）methods. The results showed that the seed viability of Kobresia robusta was low（64%）, the seed size was small（weight of one thousand seeds was 4.63 g） and the seeds were wrapped by hard seed coat, thus inhibited theseed germination and resulted in lower seed germination rate. The seeds of Kobresia robusta did not germinatewhen seeds treated with hot water, mechanical process and laminated pregermination at 20-25℃ temperature.However, after cutting the seed coat, the germination rate reached the maximum of 64% at the varyingtemperature of 25/5℃（12/12h） for 14 d when seeds were treated with 98% H2SO4（6 min） and then soaked in300 mg/L GA3（2 d）, while the other 36% of seeds still did not germinate. The results indicated that Kobresiarobusta seeds had multiple dormancy mechanisms, and the mechanical limitation of seed coat might be themajor reason of seed dormancy of Kobresia robusta.