Fruit Texture Genetic Trend Analysis And Molecular Markers Research On The Hybrid Of ’Qinguan’ And ’Fuji’ Apple

The fruit texture, one major intrinsic trait, which includes firmness, crispness, flesh, andjuiciness, is one of the most important factors that contribute to overall sensory perception ofapple and determine market acceptance. In order to develop new apple varieties with desirabletexture traits and improve breeding efficiency, in this study we analyzed the genetic tendencyof fruit texture traits by investigating the fruit texture traits with sensory evaluation andmeasuring fruit firmness of ‘Qinguan’,‘Fuji’ and their F1offspring of reciprocal crossing fortwo years. Based on these results, texture parameters, firmness and crispness of some selectedhybrids were determined by sensory evaluation and instruments, and the correlation analysiswas conducted between instrumental and sensory measurement, aiming to screen suitable fruittexture evaluation methods and parameters. Meanwhile, the markers linked to crispness werescreened by SSR technology and verified by F1population hybrid. The results were asfollows:1. Analysis of fruit texture genetic variation in apple progeny. In the research, we used‘Qinguan’,‘Fuji’ and their F1offspring of reciprocal crossing to study genetic tendency offruit texture type, fleshy, juiciness and firmness. The results showed that the fruit texture ofprogeny degraded, with tougher, harder and juiceless texture observed in F1generation than in‘Fuji’. The variation of fruit firmness was a continuous skewed normal distribution, and theinheritance transfer ability of firmness was very high. It was assumed that fruit texture traitswere quantitative traits controlled by polygenic, which showed additive genetic effect andsome non-additive effect. The hard, tough and juiceless texture characteristics of ‘Qinguan’had a high reproducibility in hybrids, indicating that the texture of ‘Qinguan’ has a highinheritance transfer ability, which needs further research in other combinations.2. The instrumental studies conjunct with sensory evaluations were utilized to measurefruit texture; correlation analysis and principal component analysis were initially applied tothe rheological data. Significant correlation was observed between fruit firmness and othertexture parameters, indicating that firmness has a decisive influence on the overall fruittexture characteristics. Fruit crispness with adhesiveness, chewiness, resilience also showedpositive correlation, indicating that crispness is also an important parameter determining the fruit texture. Fruit firmness and crispness, both reflecting the texture of the fruit firmness,were significantly positive correlated, that is to say, the fruit firmness higher and crispness ishigher. There was no significant correlation between fruit crispness sensory evaluations andother parameters, which suggested that texture parameters can not be used to evaluate fruitcrispness, texture crispness parameter values can be used to represent fruit crispness withincertain range, otherwise it can only be uesd to reflect firmness. Principal component analysisdemonstrated that fruit firmness, crispness, chewiness and cohesiveness largely determinedthe texture characteristics of the fruit.3. The SSR molecular markers linked to apple crispness. The molecular markers SSRtechnology, combined with bulk segregation analysis method were used, study on themolecular markers linked to apple crispness was conducted. By screening84pairs of SSRprimers, a molecular marker CH03a08linked to cripness with genetic distance of20.13cMwas obtained.