杉木传粉生物学的观察

观察了杉木雌、雄球花在树冠上的分布规律及开花，传粉的全过程，发现雌球花主要分布在树冠中，上部，即Ⅰ～Ⅳ年龄段，约占总量的７７％，雄球花的分布趋势与雌球相反，在相应部位仅为总量的４０％，雌球花开放期约７ｄ，可授期３－５ｄ。雄球花的撒粉期与雌球花的可授期是吻合的，传粉过程中对花粉撒落的定量测定表明：睛朗、干燥的天气伴随一定的风力是花粉传播的必要条件，对授粉后幼果的发育及胚珠所接受花粉的多寡与种子发育的

STUDY ON BIOLOGY OF POLLINATION OF CHINESE FIR

Investigation has been made into the distribution of male and female cones in the crown and the process of flowering and pollination of Chinese fir Cunninghamia Lanceolata(Lamb.)Hook.].More than three fourths of female cones are borne in the mid and top parts of the crown,i.e.,branches on the I-IV yearly sections of trunk in a 15-year-old seed orchard.In contrast,only about 40% of pollen cones are set in this area.It takes about seven days for a female cone to open and close again its bract scales,but the reception period for pollen grains in individual female cones is only 3-5 days in view of the presence of pollination drop. A quantitative analysis has showed that sunny and breezy days with low humidity are necessary for pollen to disperse.It is not the cone but seed development that is determined by the amount of pollen grains settled on ovules.It is hoped that the effective pollination,the ratio of the number of ovules settled by pollen grains to the total number of ovules, could be used as a potential parameter for predicting seed crop from a seed orchard or a seed stand.