Analysis Of Main Characters,Variety Selection And Organic Cultivation Techniques Of Lettuce

Lettuce is a global vegetable crop.It is one of the main vegetables grown in summer and autumn in zhangchengbashang area of Hebei province.The analysis of main characters,variety selection and organic cultivation techniques of heading lettuce have important practical significance for promoting genetic improvement and organic production of heading lettuce.In this paper,17 heading lettuce cultivars were used as experimental materials.The main characters,varieties selection and organic cultivation techniques of heading lettuce were studied under open field cultivation and greenhouse conditions in Zhangchengbashang area.The main results are as follows:1.Analysis of main characters of heading lettuceThe main characters of 17 heading lettuce cultivars were analyzed.The results showed that the number of leaf shape,leaf margin and bitterness intensity was widely distributed,and the distribution of leaf gloss and texture was the most concentrated.The analysis of coefficient of variation showed that the main characters of different heading lettuce cultivars varied widely,the variation range of petiole length was the largest,the coefficient of variation was 16.6%,among the leaf characters.The genetic information of petiole length,petiole thickness,number of lotus leaves,maximum ball leaf weight,maximum ball leaf weight and yield traits of single plant weight and single ball weight were abundant.The results of principal component analysis showed that the differences among different cultivars were mainly due to leaf width,Longitudinal and transverse diameter of leaf ball,plant height and leaf length.The results of correlation analysis showed that there were correlations among leaf width,plant width and maximum globular leaf weight.In order to effectively improve the yield of heading lettuce,many factors should be considered in breeding.Path analysis showed that the direct path coefficient of single bulb weight and yield was 0.655,and the indirect effect of other traits was positive,but the effect was small,indicating that the contribution of single bulb weight to yield was mainly through its own direct effect.Cluster analysis showed that 17 heading lettuce varieties showed diversityvariation and could be divided into two groups.Five morphological groups.2.Comparative test of heading lettuce varietiesUnder open-field cultivation conditions,the differences of main characters among 17 cultivar reached significant or extremely significant levels.The single plant weight,single ball weight,plant width,maximum globular leaf weight,transverse diameter and leaf width of ‘Tianping 201'and ‘Shaoshuai' had obvious advantages over the control variety ‘Marksman 101'and other varieties.Among the four varieties with shorter vegetative growth period,the single plant weight,number of globular leaves,maximum globular leaf weight,transverse diameter of globular leaf,plant width,leaf width and maximum globular leaf band of 'Royal No.2' had obvious advantages.Compared with ‘Yuhu',`avant-garde' and ‘Baisheng 115',the ‘Royal No.2' could be marketed 5 days earlier than the control variety,and the cultivation efficiency was relatively high.With its shorter vegetative growth period and quality advantages,the output value was effectively improved.Comprehensive analysis showed that ‘Tianping 201',‘Shaoshuai' and ‘Royal No.2' were three excellent varieties suitable for open-field cultivation in Zhangchengbashang area.3.Study on organic cultivation techniques of heading lettuceUnder the condition of organic cultivation in solar greenhouse,the organic cultivars and Cultivation Techniques of heading lettuce were studied.The results showed that ‘Shaoshuai' had the best comprehensive performance.Its yield,plant weight,ball weight,number of bulbs,leaf length,leaf width,plant height and plant width were slightly higher than those of ‘Marksman 101' and ‘Tianping 201'.In order to provide technical support for vegetable production in the Winter Olympic Games in 2022,the "Code of Overwintering Stubble Cultivation Techniques for Organic Food Heading Lettuce Solar Greenhouse" was developed.