降香黄檀荚果和种子生长发育规律研究

Study on Laws of Growth and Development of Dalbergia odorifera Pods and Seeds

关键词:  降香黄檀  种子  荚果  生长发育  适宜采收期

Key words:  Dalbergia odorifera  seeds  pods  growth and development  suitable harvest time

摘要:

降香黄檀(Dalbergia odorifera)为珍稀树种，天然分布的降香黄檀濒临绝迹，为保护现有的降香黄檀种质资源，本研究以广西降香黄檀荚果作为研究对象，观察荚果和种子的生长发育变化情况，并对降香黄檀种子部分生理生化指标及发芽率的变化进行测定，探讨降香黄檀荚果和种子的生长发育规律，为确定其适宜采收期提供理论支撑。结果表明：降香黄檀荚果和种子的颜色由浅绿色逐渐过渡到黄褐色，最终在盛花期后160 d后变为深褐色；荚果和种子体积大小在整个采收期中一直维持不断增长的趋势，且在盛花期后185 d开始缓慢而稳定地增长；种子含水量在盛花期后185 d后降至35%左右并趋于稳定；种子可溶性糖含量呈现先升高后降低的趋势，在盛花期后165 d最高，为45 g·kg^-1左右，直至盛花期后195 d降至42 g·kg^-1左右；种子可溶性蛋白含量呈“双峰”动态变化,盛花期后135 d达到第1个峰值，盛花期后180 d达到第2个峰值，之后开始缓慢下降；种子的发芽势、发芽率在盛花期后140-170 d达到最高，且与170 d后无显著性差异。因此，盛花期后185-200 d为降香黄檀种子的适宜采收期，种子的生长发育基本趋于稳定。

Abstract:

Dalbergia odorifera is a rare tree species,and the naturally distributed D.odorifera is on the verge of extinction.In order to protect the existing germplasm resources of D.odorifera, the pods of D.odorifera in Guangxi were taken as the research object in this study.The morphological growth and development of pods and seeds were observed,and the changes of physiological and biochemical indexes and germination rate of D.odorifera seeds were determined.The growth and development rules of pods and seeds of D.odorifera were discussed to provide theoretical support for determining the suitable harvest period.The results showed that the color changes of D.odorifera pods and seeds gradually changed from light green to yellow brown,and finally became dark brown after 160 d of full blooming stage.The size of pods and seeds maintained a continuous growth trend throughout the harvest period,and began to grow slowly and steadily 185 d after the full blooming stage.The water content of seeds decreased to about 35% after 185 d of full blooming stage and tended to be stable.The soluble sugar content of seeds showed a trend of increasing first and then decreasing,and the highest was about 45 g·kg^-1 at 165 d after full blooming stage,and then decreased to about 42 g·kg^-1 at 195 d after full blooming stage.The soluble protein content of the seeds showed a "double-peak" dynamic change,reaching the first peak at 135 d after the full blooming stage,reaching the second peak at 180 d after the full blooming stage,and then slowly decreased.The germination potential and germination rate of the seeds reached the highest from 140-170 d after the full blooming stage,and there was no significant difference with that after 170 d.Therefore,185-200 d after the full blooming stage is the suitable harvest time for D.odorifera seeds,and the growth and development of seeds basically tend to be stable.