鎘脅迫對甘藍型油菜種子萌發的影響?

摘 要：以早熟100天、新都油800、南油868、美國油王88、廣源58和豐油9號這6個油菜品種為材料，研究不同濃度鎘脅迫（0～200 mg/L）對其種子萌發及根芽生長的影響。結果表明：高濃度鎘脅迫使油菜種子的萌發出現了滯后或抑制現象，主要表現為喪失發芽活力；隨著鎘濃度的增加，不同品種的發芽勢、發芽率、活力指數、發芽指數均呈下降趨勢，發芽日數呈增長趨勢；其中發芽勢、發芽率、活力指數、發芽日數、平均發芽天數受鎘脅迫影響較小的品種為廣源58和新都油800，其次為美國油王88和南油868，而早熟100天受鎘脅迫抑制較為明顯；隨鎘濃度的增加，不同油菜品種芽長、芽鮮重、芽干重、根長、根鮮重、根干重均呈下降趨勢；不同濃度Cd脅迫下，早熟100天、豐油9號受到明顯抑制，當鎘濃度達到120 mg/L時，幾乎無可見根；南油868的芽干重降低最小；美國油王88的芽長、芽鮮重、根長、根鮮重和根干重降低幅度較小。根據試驗結果，認為美國油王88耐Cd性最強，可作為耐鎘育種研究的優異親本材料。

關鍵詞：鎘脅迫；油菜；發芽特性；幼苗生長

中圖分類號：S565 文獻標識碼：A 文章編號：1006-060X（2023）05-0037-05

Abstract：The effects of different levels （0-200mg/L） of cadmium stress on seed germination， and radicle and plumule growth of six rape cultivars （Brassica napus L.） were studied. The results showed that the germination of rape seeds was delayed or inhibited by high level Cd stress， which was mainly characterized by loss of germination vigor. With the increase of Cd concentration， the germination potential， germination rate， vigor index and germination index of the varieties all showed a decreasing trend， and the duration for 90% germination rate showed a prolonged trend. Among the six cultivars， Guangyuan 58 and Xinduyou 800 were least affected by Cd stress in terms of germination potential， germination rate， vigor index， the duration for 90% germination rate and average germination days， then Meiyou 88 and Nanyou 868， while Early Maturing 100 was seriously inhibited by Cd stress; with the increase of Cd concentration， the plumule length， bud fresh weight， bud dry weight， radicle length， root fresh weight and root dry weight presented a downward trend. Under different levels of Cd stress， Early Maturing 100 and Fengyou 9 were inhibited obviously， and when Cd concentration reached 120 mg/L， almost no roots could be seen. The bud dry weight of Nanyou 868 decreased the least， while the bud length， bud fresh weight， root length， root fresh weight and root dry weight of Meiyou 88 decreased the least. The above results demonstrate that Meiyou 88 has the strongest tolerance to Cd， which can provide excellent parental material for Cd-tolerant breeding.

Key words：cadmium stress; Brassica napus L.; germination character; seedling growth

近年來，農田土壤重金屬污染已成為威脅我國糧食安全生產的一個嚴重環境問題。鎘（Cd）是毒性最強的重金屬之一，容易在土壤—動植物—人體間富集轉移，并且在人體內具有很長的生物半衰期（10～30 a）。人體內積累過量的鎘元素可引發腎損傷、骨質疏松和癌癥等多種疾病[1]。因此，耕地鎘污染受到世界各地的廣泛關注[2]。

關于鎘脅迫對植物的生理毒害作用， 國內已經有不少報道， 主要集中在小麥、玉米[3]、水稻[4]、谷子、糜子[5]、辣椒[6]和黑麥草[7]等植物上。……