赤霉素对珍稀濒危植物银缕梅种子萌发及幼苗生长的影响

Effects of gibberellin on seed germination and seedling growth of Parrotia subaequalis,a rare and endan-gered plant species

银缕梅(Parrotia subaequalis)现为中国Ⅰ级保护植物,其自然条件下种子萌发率较低。为提高种子利用率,探究赤霉素对银缕梅种子萌发及幼苗生长的影响,本研究通过对野外采集的银缕梅种子进行不同浓度赤霉素(GA3)浸种实验。实验分别采用浓度为0、600、800、1000和1200 mg·L^(-1)的GA3浸泡48 h,而后测定种子的发芽率、发芽势、发芽指数、成苗率以及不同时期幼苗的茎长、胚根长、侧根数、叶片数、鲜重等指标。结果表明:适宜浓度GA3浸种后银缕梅种子发芽率、发芽势、发芽指数和成苗率均有提高;GA3浓度为800 mg·L^(-1)时,银缕梅种子萌发率最高,达81.1%,成苗率为92.67%,发芽势和发芽指数分别为36.67%、24.94;幼苗在GA3浓度为800 mg·L^(-1)的浸种条件下长势最佳,90 d后平均茎长为65.92 mm,胚根长44.84 mm,根数11.6,叶片数4.2片,鲜重0.444 g,与对照组相比差异显著(P<0.05);在银缕梅的人工繁育过程中,可以使用适宜浓度的GA3处理,提高种子的萌发率,缩短萌发时间。

Parrotia subaequalis,classified as a Grade I protected plant in China,exhibits low germination rate un-der natural conditions.To improve seed utilization efficiency,we explored the effects of gibberellic acid(GA3)on seed germination and seedling growth of P.subaequalis using a soaking experiment with different GA3 concentrations of 0,600,800,1000,and 1200 mg·L^(-1) for 48 h.We measured seed germination rate,germination potential,germination index,seedling rate,as well as indicators such as stem length,radicle length,lateral root number,leaf number,and fresh weight of seedlings at different stages.The results showed that applying GA3 with an appro-priate concentration enhanced germination rate,germination potential,germination index,and seedling rate of P.subaequalis seeds.The highest germination rate(81.1%)of P.subaequalis seeds was achieved at a GA3 concentra-tion of 800 mg·L^(-1),with a corresponding seedling rate of 92.67%,a germination potential of 36.67%,and a ger-mination index of 24.94.Under the conditions of soaking the seeds with a GA3 concentration of 800 mg·L^(-1),seed-lings displayed optimal growth,showcasing an average stem length of 65.92 mm,radicle length of 44.84 mm,a root number of 11.6,leaf number of 4.2,and a fresh weight of 0.444 g after 90 d,signifying significant differences compared to the control group(P<0.05).In the artificial propagation of P.subaequalis,appropriate concentrations of GA3 could be applied to enhance seed germination rates and shorten germination processes.