不同抗倒伏能力甜荞品种茎秆木质素及其单体合成特征

【目的】研究不同抗倒伏能力甜荞品种在不同生育时期茎秆木质素、总木质素单体及G型、S型和H型木质素单体含量的变化,探讨甜荞茎秆木质素及其单体合成特征。【方法】选用酉荞2号(高抗倒伏、YQ2)、信农1号(中抗倒伏、XN1)和乌克兰大粒荞(易倒伏、UD)为试验材料,试验采用随机区组设计,3次重复。分别于分枝期、盛花期和乳熟期测定其茎秆抗折力、倒伏指数、木质素含量(溴乙酰法)、总木质素单体及S型、G型和H型木质素单体含量(GC-MS法)。【结果】相同生育时期,与XN1和UD相比,YQ2茎秆抗折力大、倒伏指数小;分枝期到乳熟期,茎秆抗折力先增大后减小,在盛花期达到最大值;倒伏指数的变化存在品种差异,分枝期到乳熟期,YQ2和UD倒伏指数先增大后减小,盛花期达到最大值,XN1倒伏指数逐渐增加,乳熟期达到最大值。茎秆木质素和木质素单体含量从分枝期到乳熟期逐渐增加,YQ2木质素和木质素单体含量高于XN1和UD;在相同生育时期,S型木质素单体含量均最高,G型木质素单体次之,H型木质素单体含量均最低;分枝期到乳熟期,S和G型木质素单体含量逐渐增加,H型木质素单体逐渐降低。随着生育时期,S/G(S型木质素单体含量/G型木质素单体含量)的比率逐渐降低,G型木质素单体占总木质素单体的比例逐渐升高。【结论】甜荞茎秆木质素单体主要为S-G型。高抗倒伏品种木质素及其单体的合成特征表现为:各生育时期木质素、总木质素单体、G型、S型和H型木质素单体含量高于中抗倒伏和易倒伏品种;分枝期大量积累S型木质素单体,分枝期到乳熟期主要积累G型木质素单体。

Lignin and Lignin Monomer Synthetic Characteristics of Culm in Common Buckwheat with Different Lodging Resistance Capabilities

【Objective】 This research aims to study the content change rule of lignin, total lignin monomer, G, S and H type lignin monomer of culm with different lodging resistance capabilities of buckwheat cultivars at different stages, so as to determine the lignin and lignin monomer synthetic characteristics.【Method】The varieties of Youqiao2 (YQ2, high lodging resistance), Xinnong1 (XN1, medium lodging resistance) and Ukraine Daliqiao (UD, sensitive to lodging) were used as test materials. The field experiment arranged in a factorial randomized complete design, with three replicates. Acetyl bromide method was used to determine the lignin content of different lodging resistance varieties at different growth stages. GC-MS method was conducted to determine the content of total lignin monomer which includes G, S and H type lignin monomer. Stems in common buckwheat were used to determine stem bending force and lodging index. 【Result】 At same growth stages, YQ2 was superior in culm breaking resistance and lodging index compared with XN1 and UD. The culm breaking resistance increased firstly and then decreased from the stage of branching to milk ripe, the maximum values arrived at full bloom stage. The lodging index among different varieties changed differently, the lodging index of YQ2 and UD increased and then decreased from branching to milk ripe stage, and the maximum values arrived at full bloom stage. The lodging index of XN1 increased gradually from branching to milk ripe stage, and the maximum values arrived at milk ripe stage. The content of culm lignin and lignin monomer increased from branching to milk ripe stage. The YQ2 contained higher lignin and lignin monomer than XN1 and UD. At the same growth stage, the content of S type monomer was higher than G type monomer, and the H type monomer was the lowest. From branching to milk ripe stage, S and G type monomer increased gradually, but H type monomer decreased gradually. Furthermore, from branching to milk ripe stage, the ratio of S/G decreased, and the ratio of G type monomer to total lignin monomer increased gradually. 【Conclusion】The main type of lignin monomer of culm in common buckwheat is S-G type. At different growth stages, the content of lignin, total lignin monomer, G, S and H type lignin monomer of high resistance varieties are higher than moderate resistance and lodging susceptible varieties. The S type lignin monomer increased quickly at branching stage, and G type lignin monomer increased in a great deal from branching to maturity stage.