無子桶柑花粉發芽及花粉管生長行為觀察

Pollen germination and pollen tube behavior in 'Seedless Tankan'

施伯明(Po-Ming Shih)

《桃園區農業改良場研究彙報》 82期 (2017/12) Pp. 15-26

摘要

果實無子為柑橘優良性狀，本試驗調查無子桶柑（Citrus. tankan Hayata）花粉萌芽及自花授粉與異花授粉後花粉管生長情形，探討桶柑無子化可能機制。無子桶柑花粉體外及體內發芽率分別為10.7%及39.5%，低於海梨柑（C. tankan Hayata f. hairi Hort.）及茂谷柑（C. reticulate Blanco × C. sinensis Osbeck）；自花授粉後第3日花粉管進入花柱，愈接近花柱基部花粉管愈少，授粉後第7日少數到達花柱基部，花粉管進入子房後呈現扭轉且管內胼胝質塞不規則出現，未觀測到進入珠孔；授海梨柑花粉後，花粉管進入花柱數量較多，授粉後第5日已到達花柱基部，但進入子房後亦出現生長異常，僅少數花粉管進入珠孔。本試驗結果顯示，無子桶柑並非完全雄不稔，無子原因可能與自交不親合或胚珠及胚囊對花粉管未產生誘導作用有關。

關鍵字

柑橘 ； 雌不稔性 ； 雄不稔性 ； 自交不親合

並列摘要

Seedlessness is an important trait in citrus. The purpose of this work was to investigate pollen germination and pollen tube growth after self- or crosss- pollination to document the mechanism of seedlessness in 'Seedless Tankan' tangor (Citrus. tankan Hayata) . The pollen germination rates of 'Seedless Tankan' tangor were 10.7% in vitro and 39.5% in vivo, lower than that in 'Haili' (C. tankan Hayata f. hairi Hort.) and 'Murcott' tangor (C. reticulate Blanco ×C. sinensis Osbeck). Three days after self- pollination, the pollen tubes began to enter into the style. There was a reduction in the number of pollen tubes growing along the style, and only a few reached the base of the style at seven days after pollination. Pollen tubes became twisted and altered morphologies with irregular depositions of callose in the ovary. There was no pollen tube penetrate into the ovule through the micropyle. In cross-pollination with 'Haili' tangor, the number of pollen tubes that penetrated into the style were higher than that in self- pollination. Five days after pollination, pollen tubes reached the base of the style in every flowers, but the pollen tubes also exhibited abnormal behavior in the ovary, and only a few penetrated into the micropyle. These result indicated that 'Seedless Tankan' tangor was not completely male sterility. The mechanism of seedlessness in 'Seedless Tankan' tangor might be self-incompatibility or the ovule and embryo sac didn't provide signals orienting and directing the pollen tube on the right course.

並列關鍵字

citrus ； male sterility ； female sterility ； self-incompatibility