荞麦茎秆解剖结构和木质素代谢及其与抗倒性的关系

以抗倒伏能力不同的4个荞麦品种研究表明,荞麦茎秆抗倒伏能力与茎秆解剖结构和木质素代谢密切相关。倒伏率与茎秆抗折力参数(r=–0.907,P0.01)、木质素含量(r=–0.844,P0.01)、机械组织厚度(r=–0.881,P0.01)、茎壁厚度(r=–0.947,P0.01)、维管束面积(r=–0.846,P0.01)、机械组织层数(r=–0.806,P0.05)和大维管束数目(r=–0.709,P0.05)呈显著负相关,而与倒伏指数(r=0.842,P0.01)呈显著正相关。木质素含量与苯丙氨酸解氨酶(PAL)活性(r=0.984,P0.01)、4-香豆酸:CoA连接酶(4CL)活性(r=0.927,P0.01)和肉桂醇脱氢酶(CAD)活性(r=0.862,P0.01)呈显著正相关。茎秆木质素含量、机械组织层数、机械组织厚度、茎壁厚度、大维管束数目和维管束面积可以作为荞麦茎秆抗倒伏能力的重要评价指标。茎秆木质素含量高、机械组织层数多、机械组织和茎壁厚、大维管束数目多且维管束面积大的荞麦品种,其茎秆抗折力参数大、倒伏指数小、抗倒伏能力强。

Relationship of Anatomical Structure and Lignin Metabolism with Lodging Resistance of Culm in Buckwheat

Lodging is a major problem in buckwheat (Fagopyrum esculentum Moench) production. In this study, we investigated the relationship between anatomical structure together with lignin metabolism and lodging resistance. The results indicated that the lodging resistance of culm in buckwheat was closely related to the anatomical structure and lignin metabolism of culm. The lodging percentage was negatively correlated with snapping resistance parameter of culm (r = –0.907, P < 0.01), lignin content (r = –0.844, P < 0.01), mechanical tissue thickness (r = –0.881, P < 0.01), culm wall thickness (r = –0.947, P < 0.01), vascular bundle area (r = –0.846, P < 0.01), mechanical tissue layer number (r = –0.806, P < 0.05), and large vascular bundle number (r = –0.709, P < 0.05), but positively correlated with lodging index (r = 0.842, P < 0.01). The lignin content was positively correlated with activities of phenylalanine ammonialyase (r = 0.984, P < 0.01), 4-coumarate: CoA ligase (r = 0.927, P < 0.01), and cinnamyl alcohol dehydrogenase (r = 0.862, P < 0.01). Therefore, lignin content in culm, mechanical tissue layer number, mechanical tissue thickness, culm wall thickness, large vascular bundle number, and vascular bundle area can be used as main indicators to evaluate lodging resistance in buckwheat. Buckwheat cultivars with high resistance to culm snapping and lodging usually have high lignin content, large number of mechanical tissue layer, and large number of vascular bundle, and thick mechanical tissue and culm wall, and large vascular bundle area.