球莖甘藍低溫處理對開花影響之研究

Effecf of Low Temperature Treatment on Flower Development in Peiping Kohlrabi

沈再發(Tzay-Fa Sheen) ； 荘順中(Shun-Chung Chuang)

《中華農業研究》 28卷2期 (1979/06) Pp. 67-77

https://doi.org/10.29951/JARC.197906.0002

摘要

1.本試驗爲研究春化處理對北平球莖甘藍開花所需之低溫條件，及花之發育與值株體內成分之代謝情形。藉以瞭解其花芽發育之生理。
2.北平球莖甘藍本葉13葉（莖粗6mm）以上，才能對春化處理有感應。將達到感應之幼苗，行30天以上，8℃之低溫處理才能誘導達到開花之效果國。
3.結球成株之球莖甘藍，在8℃暗處低溫處理6週以上，也可達到開花效果。
4.成球低溫處理與花芽分化及植株體內成分之代謝情形如下：(1)在低溫處理的第一週期間，糖類含量增加，氮素含量減少，C/N率提高。(2)經一週之低溫處理後，即可引起花芽分化。於花芽分化時，糖類含量急劇增加，達一高峰，C/N率亦同。隨著低溫處理之加長，花芽分化更爲發育，但糖類含量則逐漸降低，同時值物體吸收氮素，使C/N率降低。(3)低溫處理期間長者花蕾之發育迅速，而且形成完全花。隨側芽及萼片之發育後，糖類含量愈爲降低。達開花期者，糖類含量繼續下降，C/N率更降低。不能達開花期者，則糖類及C/N率維持穩定。(4)因此，可歸結爲自低溫處理到花芽分化期糖類含量增加而氮素含量減少，形成高C/N率。於花芽分化後到抽苔期，則糖類減少或氮素含量增加，C/N率降低。
5.亞熱帶地區的臺灣，將北平球莖甘藍在2,000m之高冷地行充足春化處理後，移至溫暖乾燥之平地可達開花採種之目的。

並列摘要

1. The experiments were carried out to investigate the condition and development of flowering, associated with metabolic changes of carbohydrates and nitrogen in relation to low temperature treatment of Peiping kohlrabi in order to find the physiological causes for the flower development.
2. Peiping kohlrabi is a green vernalization type plant. The sensitivity to low temperature treatment occurs at a certain stage of the seedling's development, that is after a size of at least 13 expanded leaves (or more than 6 mm of stem diameter). The results show that a low temperature treatment of 8℃ for at least 1 month is required.
3. For the purpose of selection the mature kohlrabi were exposed at 8℃ under dark condition for 6 weeks to induce complete flowering.
4. The following metabolic changes in the swollen stems were associated with the development of flower bud differentiation: a. The metabolic changes in the swollen stems during the vernalization period showed that the content of carbohydrates increased while the total nitrogen content decreased during the first week of treatment. Especially, the sugar content in the swollen stems increased rapidly by early low temperature treatment. b. One week of low temperature treatment (8℃) lead to flower initiation after the end of exposure. At the time of flower initiation the sugar content reached its peak. The C/N ratio also was at a high level. The longer the low temperature treatment, the more floral organs developed and the more sugars were consumed while the nitrogen content gradually increased. c. The experiment showed that the longer duration of low temperature treatment not only accelerated the development of floral organs, but also promoted perfect flowering. When axillary flower bud and sepal developed, the sugar content decreased. The plants which had bolting of flowering consumed more sugars which lead to a lower C/N ratio. On the contrary, those plants with a shorter period of low temperature treatment, while maintaining a higher sugar content and C/N ratio, did not develop flower or only inperfect flower. d. It can be concluded that during the period from low temperature treatment to flower initiation increasing total sugar and decreasing nitrogen compounds contents form a high C/N ratio while in a later stage, from flower initiation to bolting, a low C/N ratio is caused by a decrease of sugar content and a increase in the content of nitrogen compounds.
5. In subtropical Taiwan the low temperature requirement for the seed production of Peiping kohlrabi cannot be fulfilled. However, it is possible, to expose plants at high altitudes (2,000m above sea level) for a period of vernalization whereafter flower development and seed production can be performed in warm and dry lowlands.