种子繁殖香根草植株的生物学特征及其病虫害初报

香根草Vetiveria zizanioides种子繁殖植株经过9个月生长，其分蘖数平均每株21个，抽穗率10％～30％，淡黄色的种子长1．5～2．5mm，宽0．6～0．8mm，呈长椭圆型；种子千粒重0．291g；平均结实率18．92％。结果表明，香根草种子繁殖植株基本与亲本保持一致。此外，其上出现蚜虫危害。

A primary report on biological characteristics and insect pest of seeding reproductive Vetiver grass

The average tillers of seeding reproductive Vetiver grass was 21 and the maximum was 30 in every plant after growing nine months. In addition, plant height was 130~200 cm, leaf length 55~100 cm, leaf width 0.5~1.0 cm, diameter of root 0.06~0.18 cm, root length 60~120 cm, root-corona ratio 46.15%~55.5%, sprouting rate was 10%~30% and maximum reached 50%, panicle length was 15~39 cm, the seed was flaxen and elliptic, length of the seed was 1.5~2.5 mm and width 0.6~0.8 mm;fruiting rate of the topmost ,the first and second side branch were 25.79%,(18.99%),11.97%,respectively. The thousand-grain weight were 0.363,0.280,0.231 g, respectively. The results showed:sexual reproductive Vetiver grass is basically as the same as parental generation, but the fruiting rate is lower.Besides, we discovered insect pests which was primary its named Aphid on the seeding reproductive plants in October and December in 2003.