干旱胁迫下沙地赤松等松科植物种子萌发特性

目的]以北方干旱区常用的3种松科植物沙地赤松、樟子松和青海云杉为研究对象,分析其种子萌发特性及对干旱胁迫的响应。沙地赤松为辽宁省固沙研究所于2014年筛选审定的新品种,目前在辽宁省生长状况良好,尚未有过其抗旱能力的相关研究。青海共和是高寒沙区,将沙地赤松与青海省常见的两种松科植物青海云杉和樟子松进行对比,以期为沙地赤松在青海引种试种提供参考。方法]采用不同浓度PEG-6000溶液模拟干旱胁迫的方法进行种子萌发试验,利用模糊隶属函数对干旱胁迫下3种松科植物的种子相对发芽率、相对胚根长、相对胚芽长、萌发胁迫指数、萌发抗旱指数和萌发活力指数等6项指标进行综合评价。结果]低浓度的PEG-6000溶液对3种松科植物种子萌发和胚根生长发育均有促进作用;随着干旱胁迫程度的加剧,3种松科植物的发芽率、幼苗鲜质量、活力指数、萌发胁迫指数、萌发抗旱指数均呈先上升后下降的趋势;种子萌发期耐水分胁迫能力为沙地赤松樟子松青海云杉。结论]沙地赤松比樟子松和青海云杉的抗旱性强,适宜在青海引种试种。

Seed Germination upon Drought Stress of Pinus densiflora Sieb. et Zucc. and Other Two Pinaceae Species

Objective] The experiment aims at estimating the seed germination characteristics and the response to drought stress of Pinus densiflora, Pinus sylvestris var. mongolica and Picea crassifolia which were widely used in arid area afforestation in north China. Pinus densiflora is a new species screened and verified in 2014 by the Liaoning Sand-Fixation Afforestation Research Institute. It grows well in Liaoning Province, and there is not any studies on its drought tolerance during seed germination. Gonghe County in Qinghai Province is a alpine sandy area. In order to provide reference for introducing Pinus densiflora in Qinghai sandy land, the tolerance of Pinus sylvestris var. mongolica and Picea crassifolia, two common sandy Pinaceae plants in Qinghai province, to drought stress were compared with Pinus densiflora.Method] Seed germination experiments were conducted using different concentrations of PEG-6000 solution to simulate the drought stress. The relative germination rate, relative root length, radicle length, vigor indexes, germination stress index and germination drought tolerance index of the three species were comprehensively evaluated by fuzzy membership function method.Result] Low concentrations of PEG-6000 improved seed germination and the radicle length of the three species. The seed germination, radicle length, seed flesh weights, vigor indexes, germination stress index and germination drought tolerance index of the three species showed a trend of increase in initial and then decrease with increasing PEG-6000 concentration. The tolerance to water stress was Pinus densiflora > Pinus sylvestris var. mongolica > Picea crassifolia.Conclusion] The drought tolerance of Pinus densiflora seed is superior to that of Pinus sylvestris var. mongolica and Picea crassifolia, which indicates that Pinus densiflora is suitable to be planted in Qinghai province.