選拔耐高溫淹水花椰菜及其相關形態與生理指標

Abstract

花椰菜(Brassica oleracea L. var. botrytis L.)為臺灣重要蔬菜，但夏季颱風豪雨常造成產量損失，加速育成夏作耐淹水品種可改善此問題。本研究依據花椰菜20 個品種/系於夏季淹水2 天後之產量，篩選'1702'、'1705'及'嬌雪'為耐高溫淹水品種，其直立葉片數最多、淹水影響指數最低；'1856'、'1858'及'1867'為高溫下不耐淹水之品種，直立葉片數最少、淹水影響指數最低。各材料28 天齡苗以50℃熱處理，'1702'、'1705'及'嬌雪'之細胞膜相對熱傷害值較低，而'1856'、'1858'及'1867'較高。苗株以35/30℃淹水24 小時，'1702'、'1705'及'嬌雪'之抗壞血酸過氧化酶(ascorbate peroxidase, APX)活性上升較快，且於排水恢復48 小時皆能維持APX 高活性，而'1856'、'1858'及'1867'之APX 活性低且上升較慢。以35/30℃淹水處理24及48小時，'1702'、'1705'及'嬌雪'之葉綠素a/b 比值顯著較'1856'、'1858'及'1867'高，總過氧化物含量較之低。苗株於35/30℃淹水10 天，'1702'、'1705'及'嬌雪'之地上部相對鮮重皆比'1856'、'1858'及'1867'高。綜上，花椰菜28 天齡苗之葉片細胞膜相對熱傷害值，苗株於35/30℃淹水24 小時之葉片APX 活性、葉綠素a/b、總過氧化物含量、淹水10 天後之地上部鮮重，以及成株之直立葉片數與淹水影響指數，可做為篩選夏作耐淹水花椰菜之生理指標，或可縮短育種時間。

Cauliflower (Brassica oleracea L. var. botrytis L.) is an important vegetable in Taiwan. Typhoons and heavy rains often occur in summer, and result in the loss of cauliflower yield. Breeding cultivars tolerant to flooding at high temperature might improve cauliflower yield in summer. In this research, 20 cultivars/lines of cauliflower were evaluated according to summer yield after 2-day flooding treatment. '1702', '1705' and 'Charming Snow' were heat- and flooding-tolerant with more erect leaves and lower flooding-affected index. '1856', '1858' and '1867' were heat- and flooding-sensitive with less erect leaves and higher flooding-affected index. In 28-day seedling stage, leaf cell membrane thermostability at 50℃ in '1702', '1705' and 'Charming Snow' were lower, while that in '1856', '1858' and '1867' was higher. After flooding for 24 h at 35/30℃, ascorbate peroxidese (APX) activity of '1702', '1705' and 'Charming Snow' raised faster and remained until draining for 48 h. On the contrary, APX activity of '1856', '1858' and '1867' were lower and also increased slower. At 24 h- and 48 h-flooding at 35/30℃, '1702', '1705' and 'Charming Snow' seedlings with higher chlorophyll a/b showed lower total peroxide content. While '1856', '1858' and '1867' with lower chlorophyll a/b exhibited higher total peroxide contents. On 10-day flooding at 35/30℃, '1702', '1705' and 'Charming Snow' had higher relative shoot fresh weight than '1856', '1858' and '1867'. In conclusion, leaf cell membrane thermostability at 50℃, leaf APX activity, chlorophyll a/b, total peroxide content after 24 h flooding, shoot fresh weight after 10-day flooding at 35/30℃ of 28-day seedling, erect leaf number and flooding-affected index of adult plant, might be used as physiological index for screening flooding tolerant cauliflower in summer to shorten breeding time.