基于主成分分析综合评价6个杂交授粉组合的马家柚果实品质

Comprehensive evaluation on fruit quality of six hybrid pollination combinations of Majiayou based on the principal component analysis

【目的】探究不同杂交授粉组合马家柚果实营养成分特征性状,综合评价杂交果实品质,为选择适宜的马家柚授粉父本提供数据支撑。【方法】通过品质指标变异系数分析、相关性分析和主成分分析对2020年广丰地区6个杂交组合马家柚果实样品共18项品质性状指标进行综合评价。【结果】单果质量、果皮厚度、蔗糖含量、柠檬酸含量等在内的共18项品质性状指标间差异显著,变异系数为6.35%~114.45%。通过主成分分析提取到5个主成分,累积贡献率可达85.001%,分别反映了果实糖酸、色泽、营养、外观、香气及苦味品质指标。其中,果实可溶性糖和有机酸各组分含量以及甜度值为评价杂交授粉马家柚果实品质的重要因子。【结论】主成分因子得分及排序表明鸡尾葡萄柚为马家柚的最佳授粉父本。

【Objective】Different hybrid pollination combinations show significant differences in fruit quality of Majiayou.However,research on cross pollination of Majiayou mainly focuses on the evalua-tion and analysis of conventional quality.There are few studies that comprehensively evaluate the sec-ondary metabolites such as important flesh color indicators like lycopene,flavor indicators like naring-in,and aroma substances based on variety characteristics.In order to provide valuable information and evaluation tools for breeders,a total of 18 pomelo fruit quality traits were used for comprehensive evalu-ation to select suitable male parents for pollination and provide data support for production.【Methods】The fruit setting rate,important secondary metabolites like lycopene and naringin,and major volatile substances of six hybrid pollination combinations of Majiayou were examined,and then the early data on 18 quality traits including single fruit weight,peel thickness,number of seeds,soluble solids,titrat-able acid,sucrose,glucose,fructose,citric acid,malic acid and sweetness value were used for coeffi-cient of variation(CV)analysis,correlation analysis,principal component analysis(PCA),and compre-hensive score ranking to evaluate the fruit quality traits of different hybrid pollination combinations in Majiayou.【Results】There were significant differences in the 18 quality traits of fruit among different hybrid pollinated combinations of pomelo,with a coefficient of variation ranging from 6.35%to 114.45%.Among them,the highest fruit setting rate hybrid combination was Majiayou×Tuyou No.4(T4)of 55.3%,while Majiayou×Cocktail grapefruit(JW)had the lowest fruit setting rate of 22.9%.The contents of lycopene,naringin,and volatile substances in the juice cells of different hybrid pollina-tion combinations of pomelo were measured.The results showed that different male parents had a sig-nificant impact on the secondary metabolites in the juice cells of Majiayou.Among them,the contents of lycopene in Majiayou×Tuyou No.1(T1),Majiayou×Tuyou No.2(T2)and T4 treatments were sig-nificantly higher than those in natural pollination(control),while there was no significant difference be-tween Majiayou×Tuyou No.3(T3),Majiayou×HB pummelo(HB),and JW treatments and control.In terms of naringin content,HB treatment significantly reduced the naringin content in the fruit,being on-ly 4.05 mg·g-1,and there was no significant difference between other treatments and control.The com-position and proportion of volatile substances in fruits of different hybrid pollination combinations were as follows:the volatile substances in the juice cells of naturally pollinated Majiayou were mainly sesqui-terpenoids,accounting for 44%;next were monoterpenoids,accounting for 24%;Aromatic hydrocar-bons accounted for 13%;Other volatile substances(aldehydes,acids,esters and aldehydes)accounted for a total of 20%.Compared to control,there were significant differences in the proportion of main vol-atile substances of different hybrid pollination combinations,specifically manifested as an increase in the proportion of sesquiterpenoids and a decrease in the proportion of monoterpenes.The proportion of sesquiterpenoids of T1 increased to 60%,which was 16%higher than that of control;Monoterpenoids only accounted for 4%,a decrease of 20%compared to control.Except for T3,the proportion of vola-tile substances of the hybrid combinations was significantly different,while the proportion of various substances of other four male parents(T2,T4,JW and HB)was similar to that of T1.With T3 combina-tion,the proportion of sesquiterpenoids and monoterpenes decreased to 34%and 9%,respectively,com-pared to control;Aromatic hydrocarbon substances increased to 16%.The proportion of other volatile substances increased to a certain extent,with aldehydes,acids,esters and aldehydes increasing by 11%,5%,5%and 1%,respectively.Analyzing the specific main volatile substances,T3 treatment with the highest content of gemacrene D.significantly reduced the content of gemacrene D in fruits,being only 11.71μg·g-1 compared to control,the decrease was 64.1%,and there was no significant difference in the fruits of the other five hybrid pollination combinations.The correlation between different indexes was analyzed.The quality traits of different hybrid pollination combinations were different,and the co-efficient of variation ranged from 6.35%to 114.45%.Correlation analysis results showed there were ex-tremely significant or significant correlations among them.The correlation analysis results indicated that there was a highly significant or significant correlation between similar indicators like sugar and ac-id components.In terms of appearance quality,there was a significant negative correlation between the number of seeds and the thickness of the fruit peel.In terms of nutritional color and flavor,ascorbic ac-id was significantly and positively correlated with fructose,glucose and malic acid,while naringin was significantly and positively correlated with ascorbic acid.The correlation results reflected consistency and also reflected differences in some indicators like fruit appearance and internal quality due to differ-ent parental choices.Principal component analysis was conducted on 18 standardized trait indicators,and a total of 5 principal components were extracted from the 18 quality indicators.The cumulative con-tribution rate of these 5 principal components reached 85.001%,indicating that the first 5 principal com-ponents had already covered most of the fruit quality trait information.The contribution rate of the first principal component was 30.416%,including soluble sugar,organic acid and sweetness value compo-nents:fructose(0.930),sucrose(0.832),glucose(0.938),citric acid(0.753),malic acid(0.722)and quin-ic acid(0.674)and those indicators had higher positive eigenvalues in PC1,indicating that as the contri-bution rate of the first principal component increased,the contents of sugar and acid related indicators increased.Finally we ranked the scores of the 5 top principal components based on their variance contri-bution rates.Among them,JW had the highest comprehensive quality score of 1.39,T1 had a compre-hensive quality score of 1.18,ranking second.The hybrid pollination treatments T3,T4,T2 and HB ranked 3-6 in sequence,and control ranked last,in which the comprehensive quality of the fruit was the worst.【Conclusion】The principal component factor score and ranking indicated that Cocktail grape-fruit was the best male pollinator for Majiayou,followed by local resource Tuyou No.1.