野牡丹属植物种子特征的初步研究

Primary Study on Features of the Seeds of Melastoma Linn Plants

以国产5种野牡丹属植物的种子为材料,对种子颜色、数量、大小、形状、千粒重和萌发率等基本特征进行观察和统计分析。野牡丹属不同植物果实中都有浅、深两种颜色种子,其数量比多在1∶2左右。种子形状为类肾形、类三角形、类半圆形、类圆形。浅色种子较饱满,能萌发;深色种子多数干瘪,不能萌发。同种植物浅色种子的千粒重约为深色种子的2倍;不同植物千粒重由大到小的顺序为:展毛野牡丹>地菍>多花野牡丹>细叶野牡丹>野牡丹。野牡丹种子的萌发率最高,为97.55%,地菍最低,为12.63%,种子萌发率与采种时期有密切关系。对种子表面做电镜扫描,多花野牡丹、野牡丹和细叶野牡丹种子表面纹饰为圆形、椭圆形或不规则突起;地菍种子表面呈不规则的皱痕;展毛野牡丹种子表面有脊和谷,脊顶部有突起,谷布满穴。

The seed features of 5 Melastoma Linn plants were studied. These features included the seed color, quantity, size, shape, 1000-grain weight and germination rate. The seeds had two color （light and dark） in all Melastoma Linn plant fruits. The rate of light color seeds to dark color seeds was 1 to 2. The shapes of seed were similar to nephroid-shaped, triangle, hemicycle or rotundity. The light color seeds were fuller than the dark ones and could germinate. The most dark color seeds were withered and could not germinate. The 1000-grain weight of light color seeds was two times than that of dark color seeds in the same plant. The sequence of the 1000-grain weight from heavy to light of different plants was M. normale D. Don, M. dodecandrum Lour., M. affine D. Don, M. intermedium Dunn, and M. candidum D. Don. Of the five plants, the seed of M. candidum D. Don yielded the highest germination frequency and that of M. dodecandrum Lour. was the lowest, which is 97.55% and 12.63% respectively. Seed germination rate was close to the period of seeds collection. Surface features of seeds were observed by using scanning electronic microscope. The results showed that M. affine D. Don, M. candidum D. Don and M. intermedium Dunn had circular, elliptic seed surfaces or irregular protuberance. The seed surface of M. dodecandrum Lour. had irregularly striate. There were ridges and vales on the seed surface of M. normale D. Don, with protuberances on the top of the ridge.