Study On The Differences In Stem Vigor Of Different Germplasm Resources Of Highland Barley In The Middle And Late Stage Of Grain Filling

Stem vitality is closely related to the material transfer rate and lodging resistance of stems in the late growth stage of crops.Stem vitality is strong,dry matter transfer rate is high,stem diameter is thick,and bending resistance is enhanced.Currently,there is no research report on the stem vitality of highland barley.This study aims to find a new evaluation method for lodging resistance breeding in highland barley based on the relationship between the aboveground stem vitality and the phenotypic traits and internal structure of the stem.Using 310 core collections studied by the research team in the early stage as experimental materials,they were planted in Lhasa and Linzhi at two different altitudes,and analyzed the stem vitality,the main stem phenotypic traits that affect lodging,and the internal anatomical structure of the stem.The results are as follows:1.The impact of different altitude regions on stem vitality varies.It is found that the average stem vitality value 151.35 mg/（g·h）planted at relatively low altitudes is higher than the average stem vitality value143.53 mg/（g·h）in high altitude regions,and the three materials with the highest stem vitality value appear in low altitude regions,namely,No.278,No.30,and No.291,with stem vitality values of 381.12 mg/（g·h）,379.07 mg/（g·h）,and 363.53 mg/（g·h）,respectively.2.Highland barley has different stem vitality values due to diffe rent sources,The analysis found that the higher the altitude of the source area,the higher the vitality of the stem appeared in different altitude planting areas.The average value of stem vitality in the h igh altitude Lhasa planting area was:175.85 mg/（g·h）from Ali>150.32 mg/（g·h）from Shigatse>145.04 mg/（g·h）from Lhasa>142.03 mg/（g·h）from Shannan>134.49 mg/（g·h）from Linzhi>133.48mg/（g·h）from Changdu;In the relatively low altitude Linzhi planti ng areas,the same phenomenon occurs in Ali 206.11 mg/（g·h）>Sh igatse 163.51 mg/（g·h）>Lhasa 148.65 mg/（g·h）>Shannan 142.54 m g/（g·h）>Linzhi 141.44 mg/（g·h）>Changdu 139.90 mg/（g·h）.3.The stem vitality in Lhasa and Linzhi planting areas is mainly distributed in grades II and III,i.e.weak and medium;There are 160varieties that share or have high stability within the same level in two planting areas,namely,I（0）,II（68）,III（61）,IV（17）,and V（14）.Among them,the varieties with high stability in Level II are the most,and the varieties with high stability in Level V are the least.4.Select 30 materials with strong stem vitality value and 30 materials with weak stem vitality value for analysis.In the first and second internodes of the base,the fresh weight,dry weight,length,diameter,wall thickness,bending resistance,and plumpness with strong stem vitality value are higher than those with weak stem vitality value;The correlation analysis showed that:in the first internode of the base,the vitality value of 30 materials with strong vitality was significantly positively correlated with diameter and flexural strength,with correlation coefficients of 0.672^**and 0.835^**;The vitality values of 30 materials with weak vitality values were significantly positively correlated with fresh weight,diameter,and flexural strength,with correlation coefficients of 0.488^**,0.575^**,and 0.697^**;In the second internode of the base,30materials with strong vitality had a significant positive correlation with diameter and flexural strength,with correlation coefficients of 0.740^**and0.852^**,and a significant negative correlation with internode length,with a correlation coefficient of-0.371^**;The correlation coefficients between stem vigor and fresh weight,diameter,and bending resistance of 30materials with weaker vigor values were 0.401^*,0.485^**,and 0.490^**,respectively;This indicates that the stronger the vitality and diameter of the stem,the stronger the bending resistance;Based on the regression analysis of 30 stem vitality test materials from the first basal internode,it can be seen that the stronger the stem vitality value,the stronger the bending resistance of the first basal internode;From the regression analysis of 30 stem vitality test materials from the second basal internode,it can be seen that the stronger the stem vitality,the stronger the bending resistance,the greater the plumpness,the longer the internode,and the greater the fresh weight of the second basal internode.5.The analysis of stem vitality and internal structure shows that the epidermis,sclerenchyma,parenchyma,mechanical tissue,large vascular bundle area,and small vascular bundle area with strong stem vitality in the second internode at the base are larger than those with weak stem vitality;In the correlation analysis,the vitality values of 30 materials with strong vitality were significantly and positively correlated with large vascular bundle area,small vascular bundle area,and sclerenchyma,with correlation coefficients of 0.936^**,0.916^**,and 0.883^**,while the stem vitality values of 30 materials with weak vitality values were significantly and positively correlated with large vascular bundle area,small vascular bundle area,with correlation coefficients of 0.824^**,and 0.658^**;From the regression analysis of 30 stem vitality test materials from the second basal internode,it can be seen that the stronger the stem vitality value is,the larger the area of the large vascular bundle,the larger the area of the small vascular bundle,and the larger the thickness of the tissue.