白花树种子生物学特性

白花树Styrax tonkinensis种子具有休眠性。对江西吉水种源的白花树种子形态结构特征、千粒质量、吸水性能、生活力及不同质量浓度赤霉素(GA3)对种子萌发特性影响等方面进行了系统研究,以期找到解除休眠的方法。吸水性能设置酸蚀、去种壳和完整等3种前处理,生活力采用2,3,5-氯化三苯基四氮唑(TTC)染色法,萌发特性设置250~1 500 mg·L-1共8个不同质量浓度。结果表明:种子由外种皮、内种皮、胚乳、胚根、胚芽、胚轴和子叶组成。2011年和2012年的种子平均长度和宽度为8.77,6.81 mm和7.91,5.20 mm,种子千粒质量分别为136.70 g和95.68 g。对3种不同处理的种子吸水性能进行测定。结果表明,去壳种子吸水性能优于酸蚀和完整的种子。种子生活力的TTC染色检测结果表明,2011年产的种子生活力为97.78%,储藏1 a后的种子生活力仍高达94.44%。不同质量浓度GA3对种子处理结果表明,促进种子萌发及幼苗生长的最适质量浓度为1 500 mg·L-1。图3表2参10

Seed biological characteristics of Styrax tonkinensis

The seeds of Styrax tonkinensis have dormancy. Seed biological characteristics of  Styrax tonkinensis including morphological structural features，1 000-grain weight，water absorption，viability，and the effect of seed germination with GA₃，from Jishui of Jiangxi Province were studied in 2011 and 2012. Seed water absorption was tested with 3 pretreatment treatments of etching，shelling，and untreated. Seed viability testing methods utilized TTC staining. Seed germination test with 7 different treatments of GA3 from 250-1 500 mg·L^－1. Results showed that the seed consisted of exopleura，endotesta，endosperm，radical，germ，hypocotyls，and cotyledons. In 2011 the average for seeds collected was：length-8.77 mm，width-7.91 mm，and 1 000-grain weight-136.70 g；and in 2012 the average was length-6.08 mm，width-5.20 mm，and 1 000-grain weight-95.68 g. The seed water absorption ability tested by 3 different treatments showd that seeds without exopleura had the best water absorption. The viability of seed tested by the TTC staining method showed，seed viability with TTC staining for seeds collected in 2011 was 97.78%. After being stored for one year，viability was still 94.44%. Seeds treated with GA₃ showed improved seed germination and seedling growth with the best concentration being 1 500 mg·L^－1. ［Ch，3 fig. 2 tab. 10 ref.］