不同环境因子对海三棱藨草种子及球茎萌发影响的研究

Studies on the effects of different environmental factors on the germination of Scirpus mariquete seeds and corms

海三棱藨草(Scirpus mariquete)是一个在滩涂潮间带原生裸地上首先定居的先锋种,是我国特有的盐沼植物。通过分析海三棱藨草种子和球茎的物理特性及室内正交试验研究其萌发的生物学特性,探究不同环境因子(温度、盐度、淹水深度)对该物种种子和球茎萌发的影响,本研究采用3因素5水平的正交试验进行探究,结果表明:海三棱藨草种子和球茎最佳萌发的环境因子组合均为温度为34℃、盐度为4‰、水深为0cm,最佳组合下种子发芽率为(81.82%±1.85%),显著(p<0.05)低于球茎的(88.88%±2.31%);海三棱藨草种子萌发对温度有较广的适应性,18—42℃都可以萌发,26—34℃萌发率较高且无显著差异(p>0.05);不同盐度下海三棱藨草种子的萌发率有较大的差异,海三棱藨草的种子在盐度为0—4‰的环境下发芽率最高。结论认为,影响海三棱藨草种子萌发的关键因素依次为盐度、温度和水深,影响海三棱藨草球茎的关键因素依次为盐度、水深和温度。海三棱藨草种子比球茎具有更强的耐环境胁迫能力,但是海三棱藨草球茎在最佳条件下比种子具有更高的发芽率。本研究为探究长江口湿地海三棱藨草退化的原因及其保护提供理论依据。

Scirpus mariquete roots originally in the primary bare land in intertidal zone as a pioneer species,which is also an endemic salt marsh plant in China.In this study,we analyzed the physical characteristics of Scirpus mariquete seeds and corms.The biological characteristics of their germination was also studied through an orthogonal test.To elucidate the influence of different environmental factors(temperature,salinity,flooding depth)on the germination of S.mariquete seeds and corms,an orthogonal test,three factors,five levels each,were conducted.The results showed that the best combinations for S.mariquete seed and corm germination were temperature(34℃),salinity(4‰)and water depth(0 cm)under which the seed germination rate was 81.82±1.85%(p<0.05)significantly less than 88.88±2.31%of corms.S.mariquete seed germination had a widely adaptability to temperature(18 to 42℃),and a higher germination rate was observed at 26-34℃,no significant difference(p>0.05)was found within the range.The germination rate of S.mariquete seeds had a significant difference among different salinities.When the salinity was 0-4‰,the germination rate of the seeds of S.c mariquete was the highest.We concluded that the key factors affecting the seed germination of S.mariquete seed are salinity,temperature and water depth while those affecting the germination of S.mariquete corms are salinity,water depth and temperature as were draw from the principal component analysis.The seed of S.mariquete has a stronger resistance to environmental stress than corm does.But the germination rate of corms is higher than that of seeds under the optimum conditions.This study provided a theoretical basis for exploring the causes of blackcurrant degeneration and its protection in Yangtze River estuary wetland.