單為生殖在結球白菜育種上利用之研究（二）利用化學藥品增進單為生殖之結子率

Studies on Utilization of Parthenogenesis in Breeding of Brassica pekinensis (Ⅱ) To Increase the Percentage of Parthenogenesis Seed Setting with Chemicals

十字花科的單為結實率一向非常低，本試驗以NAA 1, 5, 10 ppm及以硼酸1, 5, 10 ppm處理去雄後的結球白菜柱頭（品種有漳蒲早生、嘉義早生、西湖早生、清和早生、清明早生、30日早生、與農早生、黑夜早生），而以大葉芥菜、大白（木戈）蘿蔔、青花菜分別為父本。結果顯示NAA 1ppm以及硼酸1, 5, 10 ppm處理的，單為結實率高達12%以上，而不處理的只有1.2%。又如母株去雄後僅處理NAA 1ppm或硼酸1, 5, 10 ppm而不授以他種花粉依然有1-3%的結實率，此更能證明傾母後裔乃由未授精的卵母細胞發育而來。至於這些種子是由減數分裂失敗而來，抑是單位體卵細胞加倍而來，還是如作者在前報中所云兩者都有可能，則尚待研究。

There is always a low percentage of parthenogenesis seed setting in cruciferous vegetables, especially chinese cabbage In this study, we treated the plants with a NAA and a boron solution on the stigma after emasculation to induce a higher percentage of parthenogenesis seed setting. The results indicate that NAA 1 ppm and Boron 1, 5, 10 ppm increase the percentage significantly. Otherwise, we derived seeds from unpollinated buds by treating with NAA or Boron solution, Thus, the results showed that maternals come from unfertilited eggs. Whether those false hybrid seeds come from diploid eggs or haploid eggs has not been understood yet, and is valuable for future study.