蕓苔屬蔬菜自然雜交率之研究（異數染色體種類間自然雜交之難易）

Studies on Interspecific Crossing of Genus Brassica under Natural Conditions Possibility of Natural Crossing among Some Brassica spp. with Different Chromosome Number

一、本研究開始於民國五十二年八月至五十三年六月底結束，研究地點在海拔1000公尺之西實農場，氣候穩定可靠，所用材料（一）金門早生球莖甘藍n=9，（二）天津竹筒青白菜n=10，（三）四川榨菜a=18。二、三種異數染色體之蕓苔屬蔬菜，天然混合栽培採種時，經此次實驗結果，所收種子，立刻播種，作幼苗純度檢查，仍可保持固有特微不變，證明混合採種時，不易雜交。三、用人工花蕾授粉雜交時，正反交結果，各組合中雖有極少數花朵具有親和力，但所結之莢果不發育，更無種子可言，其中雖亦有少數種莢，發育良好，但種子完全不充實無發芽力。四、人工花蕾授粉雜交，如此困難成功，推論自然花粉雜交，則更難混合，因此可斷定混合栽植採種或隔離不遠採種時，無慮花粉雜亂。

1. The present study was carried out out from August 1963 to June 1964 at the Shi-Pao Farm of Central Taiwan (1,000 meters above sea level), where the whether conditions are comparatively steady. The materials used are: (1) Brassica oleracea Linn, var, caulorapa Linn. (Kinmen Early Kohlrabi, n=9) (2) B. Pekinensis Rupr. (Tientsing Chutong Pai-Tsai, n=10) (3) B. juncea Coss. Var. tumida Tsen et Lee (n=18) 2. Open crosses were tried in the field where the test 3 species were planted in the same spot, the seeds obtained from the field were sown immediately after harvest and used for further examination on morphological characters. From the results obtained, it seemed that interspecific hybrid did not occur. 3. Reciprocal crosses among materials mentioned above by artificial pollination were also studied, and only a few numbers of pods and seeds were obtained from some cross combination, but all of the seeds did not have germinating ability in spite of the fact that the seeds used were from the well developed pods. 4. From the results of this experiment, it seems difficult to produce interspecific hybrids at any cross combination by or artificial pollination.