韮菜開花習性之研究

Studies on the Blooming Habits of the Chinese Leek

為求瞭解韮菜之開花習性以利育種工作之進行，筆者將韮菜之開花方式，開花盛期，授粉方式及自交率等習性詳加觀測，以求知有關之知識。茲將試驗結果摘述於下：1.韮菜雖為雌雄同花植物，但柱頭在雄蕊謝後8～16小時方伸張成熟，故小花內之自交很難發生。2.—朵小花之花期約為72小時，前32小時為雄蕊成熟期，後40小時則為雌蕊張大有效期。3.—花軸之花期在30至60天之間，小花由外向內開放，為典型之無限花序；其結實小花數目在28至85朵間，早開小花有較易結實之趨勢。4.8. 9. 10三個月為一般葉用品種之開花期，11及14時則為一天中小花之開放盛期；至於年花種則在早上8時左右開花最多。5.韮菜為蟲媒花，放任自然蟲媒，其結實率高達90%以上，若套袋不授粉則不能結實。6.韮菜雖為異交作物，但同一花軸之自交極易成功，尤以硬骨大葉種為然，其自交結實率高達76.84%。7.同一花軸之自交效果，以用細尖鑷子較用毛筆為強。8.下午2時左右進行純化授粉之效果最好，故為一天中之適當授粉時間。

Knowledge of the blooming habits of the Chinese leek is a prerequisite for its breeding. The necessary information was obtained through observation on the blooming habits, anthesis, appropriate pollination methods and periods, and the fertility percentage of self-pollination in an umbel of the Chinese leek. The results of this experiment are summarized as follows: 1. Even though the Chinese leek is an hermaphroditic plant, its self- pollination in a single flower occured infrequently. The Chinese leek's stigma did not reach maximun le-ngth and maturity until 8~16 hours after its pollen had been shed, because the Chinese leek is a protandry. 2. The anthesis of a single flower requried about 72 hours. During the first 32 hours, six stamens opened and shed. The stigma then dehisced in a three-lobed form and lived for about 40 hours. 3. The period of flowering of an umbel was 30~60 days. Flowers bloomed inward and showed a typical interminal inflorescence. Each umbel contained 28~85 fertile flowers. The earlier the flower opened the easier for its fruit to set. 4. August, September and October were the flowering periods of the Chinese leek in the year; 11 AM and 2 PM were the anthesis of a day, but the anthesis of ever-blooming varieties were at 8 AM. 5. The Chinese leek usually was cross-pollinated by insects, which increased its fertility about 90% under natural conditions. Without artificial or insect-induced pollination in a bagged umbel, no fruit-set was found. 6. Although the Chinese leek is an alligamous crop, it showed a high degree of self-pollination within flowers of the same umbel. Yunlin large-indurate-leek (hard-rib and broad-leaf var.) had the highest self-fertility percentage amoung the various varieties in Taiwan reaching a value of 76.84%. 7. The use of needle-forceps were found to be superior to the brush-pen in self-pollination of flowers within an umbel. 8. During the day, 2 PM pollination gave the highest fruit-setting rate in this experiment.