Comprehensive Evaluation And Genetic Trend Analysis Of Fruit Meat Quality Of 50 Watermelon Germplasm Resources

As an indispensable part of watermelon flesh quality and an important indicator for evaluating its commercial value,flesh texture not only directly affects the taste of the flesh and consumers’ choices,but also affects the storage and transportation of the flesh.To comprehensively evaluate the characteristics related to watermelon flesh texture,establish a reasonable and healthy flesh texture evaluation system,and clarify the genetic tendency of indicators such as flesh texture,It can provide reliable theoretical basis and practical guidance for the selection of parents and the selection of hybrid offspring in hybrid breeding.This study used 50 watermelon germplasm resources as experimental materials to systematically identify and evaluate the fruit flesh quality.Diversity analysis,correlation analysis,cluster analysis,factor analysis,and other methods were used to comprehensively study the diversity and differences of its fruit flesh quality;In addition,9 watermelon germplasms were selected as parents to prepare F1 hybrid combinations,and various evaluation indicators such as ultra-high,ultra-low,and genetic transmissibility of watermelon fruit quality were analyzed to comprehensively evaluate the genetic trend of fruit quality.The main results are as follows:1.The 12 flesh traits of 20 watermelon germplasms,including 4 basic physical and chemical traits(soluble solids content,pectin content,titratable acid content and hemicellulose content)and8 TPA texture analyzer traits(hardness,brittleness,chewiness,adhesiveness,cohesion,resilience,adhesiveness and elasticity),the variation range of their genetic variation coefficient is15.1%～89.0%,and the diversity index of pulp taste is 1.33.2.In the correlation analysis of watermelon flesh texture analyzer indicators,the correlation coefficient between hardness and brittleness is 0.976,and the correlation coefficient between chewiness and adhesiveness is 0.922.Most texture analyzer indicators have correlation coefficients greater than 0.8,showing a highly correlated characteristic with each other.3.The pulp texture and physical and chemical properties of 50 germplasm resources were constructed into four main factors,which were distributed as F1 main factor("choking factor"),F2 main factor("quality factor"),F3 main factor("sticky cotton factor"),and F4 main factor("compound factor").By calculating the comprehensive scores of 50 watermelon germplasm resources for quality ranking,it was found that the 1059 watermelon germplasm has the best comprehensive quality.4.Using systematic clustering method,50 germplasm resources were divided into six categories based on taste and hardness,with each category exhibiting distinctive traits.Among them,the first category was characterized by crispy and hard taste with the highest hardness,ranging from 3448.8g to 4834.1g in hardness;The second type has a slightly crispy texture,soft sand,and high hardness,ranging from 2185.2g to 3327.1g;The third type has a crispy,soft,and sandy texture with moderate hardness,ranging from 900.5g to 1300.1g;The fourth type of taste is crispy and sandy,but the hardness is relatively small,ranging from 1496.3g to 2185.2g;The fifth type has a hard taste,with a hardness of 5585.43g;The sixth category is the hardest taste but the hardness is 6928.97 g.5.In the analysis of genetic trends in the physicochemical properties and texture traits of the flesh of 10 F1 offspring,it was found that the soluble solid content,hardness,brittleness,and elasticity of the flesh have strong hybrid advantages,showing a genetic trend towards higher parents;The pectin content,adhesiveness and chewiness of pulp all have relatively weak heritability,showing a tendency to lower parents.