直播条件下水分胁迫对白及种子萌发的影响

Effects of Water Stress on the Germination Process of Bletilla striata Under Direct Seeding Conditions

为解决白及直播种子萌发不稳定的问题,本研究以椰糠为基质,设置4个含水量梯度,研究直播条件下水分胁迫对白及种子萌发过程的影响。结果表明:种子直播后主要经历吸水膨胀成球状体(a)、球状体转绿(b)、球状体一端长出第一片叶(c)、长出丛毛状假根(d)、长第二片叶(e)和长根(f)6个阶段。不同含水量基质上,最高萌发率为68.3%,最低萌发率为0,总体趋势为随着基质含水量增加萌发率提高,从不同阶段转化率来看,水分条件影响的关键阶段为b和e阶段;从萌发时间看,最终完成长根需要82.3~86.7 d,总体趋势随着基质含水量的增加萌发时间减少,其中从播种到c阶段转化时间随基质含水量增加而减少,e到f阶段转化时间随基质含水量增加而增加。基于以上结果,在白及种子直播育苗生产中,可以在萌发前期增加基质含水量,最后阶段适当降低基质含水量来提高萌发率,缩短萌发时间。

In order to address the issue of unstable germination in Bletilla striata under direct seeding conditions,we examined the impact of water stress on the germination process of B.striata.Coconut bran was used as substrate and four water content gradients were established.The result revealed that the germination process of B.striata seeds can be divided into six stages:bulbous expansion,globule turning green,first leaf growth,hairy pseudoroot growth,second leaf growth,and root growth.The result showed that the germination rate ranged from 0%to 68.3%,with higher water content leading to higher germination rates.The key stages influenced by water conditions were the globule turning green and the growth of the second leaf.Additionally,the time required for root growth ranged from 82.3 to 86.7 days,with higher water content leading to shorter germination times.The study concluded that using a higher water content substrate in the earlier stages and decreasing water content in the later stages can increase germination rates and shorten germination times in direct seeding production.