Relationship between lodging resistance of oats and the basal internode stem characteristics and lignin synthesis北大核心CSCD

Lodging is one of the important factors affecting yield and quality in oat crops. This research studied the physiological mechanisms of lodging resistance in oats，with a view to guiding future breeding. Mengyan 1 and Bayan 6 oat were included in this study as lodging-resistant varieties，while Dingyan 2 and Qingyin 2 were included as lodging-susceptible varieties. Data were collected on the morphological characteristics of basal elongation and differences in the contents of acid detergent fiber，neutral detergent fiber，cellulose and lignin and activities of key enzymes，for these oat cultivars with different lodging susceptibilities，so as to investigate the relationship between the lodging resistance of oats and the morphological characteristics and lignin content and synthase activity in the second-phase elongation at the base of stem. It was found that the amount of lodging among resistant cultivars was lighter and the lodging rate was lower than that of cultivars. The lengths of the second internode at the stem base of lodging easy cultivars were 34. 17% higher than those of lodging resistant cultivars. The internode diameter，stem wall thickness，stem weight，density，diameter，force and stem puncture force values of lodging resistant cultivars at the second internode of the stem base were，respectively，29.11%，26. 18%，25.80%，27.97%，34.61%，36.23% and 36. 60% higher than those of lodging-susceptible cultivars. The stem lignin and cellulose contents of cultivars resistant to lodging were significantly （P<0. 05） higher than those of cultivars susceptible to lodging. Lignin content was significantly （P<0. 01） positively correlated with the internode breaking force and puncture strength of the second internode at the stem base （r=0.9862 and r=0.9638，respectively），and significantly negatively correlated with the observed lodging rate（P<0.05，r=−0.9407）. Lignin synthetase tyrosine ammonialyase，phenylalanine aminotransferase，cinnamyl alcohol dehydrogenase and 4-coumaric acid of CoA ligase in stems of lodging-resistant cultivars showed higher activities，resulting in accumulation of lignin at the internodes of the second elongation at the base of stem，which increased the lignification of cell walls and the mechanical strength of stems，and thus enhanced lodging resistance of the oats. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.

Relationship between lodging resistance of oats and the basal internode stem characteristics and lignin synthesis

Lodging is one of the important factors affecting yield and quality in oat crops. This research studied the physiological mechanisms of lodging resistance in oats， with a view to guiding future breeding. Mengyan 1 and Bayan 6 oat were included in this study as lodging-resistant varieties， while Dingyan 2 and Qingyin 2 were included as lodging-susceptible varieties. Data were collected on the morphological characteristics of basal elongation and differences in the contents of acid detergent fiber， neutral detergent fiber， cellulose and lignin and activities of key enzymes， for these oat cultivars with different lodging susceptibilities， so as to investigate the relationship between the lodging resistance of oats and the morphological characteristics and lignin content and synthase activity in the second-phase elongation at the base of stem. It was found that the amount of lodging among resistant cultivars was lighter and the lodging rate was lower than that of cultivars. The lengths of the second internode at the stem base of lodging easy cultivars were 34.17% higher than those of lodging resistant cultivars. The internode diameter， stem wall thickness， stem weight， density， diameter， force and stem puncture force values of lodging resistant cultivars at the second internode of the stem base were， respectively， 29.11%， 26.18%， 25.80%， 27.97%， 34.61%， 36.23% and 36.60% higher than those of lodging-susceptible cultivars. The stem lignin and cellulose contents of cultivars resistant to lodging were significantly （P<0.05） higher than those of cultivars susceptible to lodging. Lignin content was significantly （P<0.01） positively correlated with the internode breaking force and puncture strength of the second internode at the stem base （r=0.9862 and r=0.9638， respectively）， and significantly negatively correlated with the observed lodging rate （P<0.05， r=-0.9407）. Lignin synthetase tyrosine ammonialyase， phenylalanine aminotransferase， cinnamyl alcohol dehydrogenase and 4-coumaric acid of CoA ligase in stems of lodging-resistant cultivars showed higher activities， resulting in accumulation of lignin at the internodes of the second elongation at the base of stem， which increased the lignification of cell walls and the mechanical strength of stems， and thus enhanced lodging resistance of the oats.