金丝李果实、种子形态分化及外源物质对种子萌发和幼苗生长的影响

Morphological differentiation of Garcinia paucinervis fruits and seeds and effects of exogenous substances on its seed germination and seedling growth

通过采集3个天然种群的金丝李(Garcinia paucinervis)果实,观察果实和种子的形态性状,分析其种群内和种群间的形态分化,观察不同种群种子萌发和幼苗生长的规律;采用四种植物生长调节剂和两种化学药剂,研究浸种对金丝李种子萌发和幼苗生长的影响。结果表明:金丝李种子长2.48~3.08 cm、宽1.49~1.67cm、百粒重392.50~438.18 g;3个种群果实和种子已产生明显的形态分化,胡润种群多数表型性状值在3个种群中最小,安宁种群的果实和种子偏圆,弄岗种群偏窄;在种群内部,果实和种子重量的分化较显著,整体形态较稳定;在萌发过程中,种子留存,不定根逐渐取代胚根成为主根;3个种群的萌发过程均缓慢,中间阶段几乎停滞,出苗极不整齐,萌发率表现为安宁种群(78.33%)>弄岗种群(55%)>胡润种群(48.33%),种子存在休眠;从种子萌发来看,以80 mg·L^(-1)的6-BA浸种24 h处理效果最好,萌发时滞最短、萌发率最高、平均萌发时间最短;结合幼苗生长情况来看,10~50 mg·L^(-1)的6-BA和500 mg·L^(-1)的GA_3处理均适宜,以50 mg·L^(-1)的6-BA效果最佳。低浓度的KNO_3和NH_4NO_3能提高萌发率,但未显著加快萌发进程,IAA和NAA对种子萌发和幼苗生长有抑制作用。该研究结果为金丝李的遗传多样性提供了形态学资料,为更好地保护、开发和利用这一珍贵树种提供了科学依据。

Based on three natural populations of Garcinia paucinervis,the morphological characters of fruits and seeds were observed and measured,morphological differentiations within and among different populations were analyzed,then the laws of seed germination and seedling growth were observed,and the effects of four plant growth regulators and two chemicals on seed germination and seedling growth were studied as well.The results showed that the lengths and widths of G.paucinervis seeds were 2.48-3.08 cm and 1.49-1.67 cm,respectively.The hundred seed weight was 392.50-438.18 g.There were evident morphological differentiations among fruits and seeds of three populations,and most of phenotypic traits of HR（Hurun Town）population were the smallest among three populations.The fruits and seeds of AN（Anning Township）population were rounder,nevertheless which of NG（Nonggang Nature Reserve）population were slenderer.Within populations,the differentiations of fruit and seed weight had relatively evident characters,while their overall shapes had relatively stable characters.The seeds were preserved during seed germination,and adventitious roots eventually replaced the radicles and then became taproots gradually.The germination processes of three populations were slow,the intermediate stages of the processes were almost stagnant,and the emergences of seedlings were very irregular.The order of germination rate of three populations was AN（78.33%）NG（55%）HR（48.33%）.Therefore,the seeds of G.paucinervis had dormancy characteristics.In terms of seed germination,the 6-Benzylaminopurine（6-BA）treatment with 80 mg·L^（-1）soaked for 24 h had the best effect,with the shortest germination time lag（GTL）,the highest germination percentage（GP）,and the lowest mean germination time（MGT）.In respect of germination,in combination with the growth of seedlings,both 10-50 mg·L^（-1）6-BA and 500 mg·L^（-1）gibberellic acid（GA_3）treatments were better,and 50 mg·L^（-1）6-BA was the best treatment for promotion effect,especially.The low concentration of KNO_3and NH_4NO_3solution could increase GP,but they did not significantly accelerate germination processes.Indole-3-acetic acid（IAA）and 1-Naphthylacetic acid（NAA）could even inhibit seed germination and seedling growth.The results can provide morphological data for genetic diversity of the rare and endangered plant G.paucinervis,and provide scientific information for better protection,development and utilization of valuable G.paucinervis.