| Cabbage(Brassica pekinensis.ssp.(Lour.)Rupr.)is a leafy vegetable of the Brassica genus of the cruciferous family.It originated in China and has a wide cultivation area,high yield and large consumption.With the improvement of people’s living standards,higher requirements are put forward for the quality of cabbage crops.Among the factors that affect the quality of cabbage,lignin occupies an important position.However,the research on lignin in cabbage is rarely reported at present.Therefore,analyzing the content and distribution characteristics of lignin in cabbage and digging out the key regulatory genes of lignin can provide a theoretical basis for the breeding of high-quality germplasm.In this study,the method for determining the lignin content of cabbage was optimized.As the same time,91 materials were tested to understand the relationship between the lignin content and the materials.The microstructure of 15 pieces of cabbage materials was observed to understand the distribution of lignin in the xylem of cabbage crops.Genome-wide association analysis was performed on the lignin content of 91 cabbage materials.The key regulatory genes of lignin were initially located,providing a theoretical basis for screening high-quality cabbage crop germplasm resources.The main findings are as follows:In this study,post-acetylation lignin has characteristic absorption peak at 280 nm to establish a method for colorimetric determination of lignin content of Chinese cabbage,the reaction conditions were:30%volume fraction of acetyl bromide,the reaction temperature 70℃,the reaction time 40 min.This method can determine the lignin content of cabbage quickly,accurately and at low cost.The lignin content of 91 materials was determined and analyzed that ranged from 120-730 mg/g,which was in line with the normal distribution.Most of the materials are in the range of 170-370 mg/g.That is moderate type.For example,the leaf color is light green,and the early,middle and late maturing materials are distributed separately.There is no obvious dividing line in material.Microscopic observation was made on the petiole vascular bundles of 15 different types of cabbage materials.The observation results are as follows:The petiole tissue of cabbage belongs to the parallel vascular bundle.The number of vascular bundles of different inbred lines ranged from 6-14 and the difference was not significant.There was no significant correlation between the level of lignin content and the number of vascular bundles.With the progress of vegetative growth,the number of vascular bundles did not change.But the deposition of vascular bundles the degree of lignification were increased.This study has important reference significance for selecting the appropriate harvest period of cabbage crops and timely stopping the increase of lignification.The whole genome re-sequencing of 91 Chinese cabbage materials was carried out.After quality control and filtering,218.56G of high-quality data and a SNP set containing 474,900 mutation sites were obtained.When r~2 attenuates from the maximum value of 0.68 to 0.34,the corresponding genome-wide attenuation average LD is 15.1kb.We predicted five candidate genes Bra003317,Bra003318,Bra003319,Bra015640 and Bra015641 related to the lignin content of cabbage crops;Bra022538,Bra018084,and Bra023190 genes related to soluble sugar;Bra036053,Bra036055 and Bra036080 genes.related to Tu MV resistance,... |
PDF Full Text Request