该选题涉及农业领域，具体包括果实的成熟衰调控研究。果实质地直接影响了采后果实的食用品质和贮藏品质。果实的质地变化包括软化外和木质化，主要取决于果胶，纤维素，半纤维素，木质素等细胞壁物质的质和量。果实木质化的特征在于细胞壁中硬度和木质素合成增加，一般出现在少数水果或胁迫条件下，如枇杷的冷害，对山竹果皮的机械损伤，病苹果果实组织和梨果实石细胞等。近几年的研究发现，果实木质素合成调控能够很好的影响果实的商品价值。该选题可以拓展人们以往对果实品质的观念，了解到果实不仅具有软化质地，而且也会发生木质素，并且了解木质化发生的机制。本选题针对我国梨、桃、枇杷等果实出现的采后木质化现象，严重影响了果实的外观品质、食用品质和贮藏品质等问题提出的。拟深入分析影响果实木质化发生的功能基因及转录因子等协同调控的分子机制，完善了果实质地变化的理论依据，为生产上解决果实采后贮藏提供科学依据。

Chapter 1 Ligninassociated Genes Expression Pattern in Pear Fruit
I Introduction
II Materials and Methods
III Results
IV Discussion
Chapter 2 The Expression Pattern of Seven PcEXPA Genes of ‘Chili’ and ‘Whangkeumbae’ Pear during Fruit Postharvest Storage
I Introduction
II Materials and Methods
III Results
IV Discussion
Chapter 3 Effects of Preharvest Calcium Treatment on the Storage Characters of Hard End Whangkeumbae Pear and the Expression Analysis of PpEXPA2
I Introduction
II Materials and Methods
III Results and Analysis
IV Discussion
Chapter 4 Altering PpCAD2 and PpEXP2 Gene Expression Impacts Lignification in Transgenic Tobacco Plants
I Introduction
II Materials and Methods
III Results
IV Discussion
V Conclusions
Chapter 5 The Heterologous Expression of PpCAD2 in Tomato ‘MicroTom’ Verified Its Function in Affecting Lignin Content
I Introduction
II Materials and Methods
III Results and Discussion
IV Conclusions
Chapter 6 PpNAC187 Was Involved in the Lignin Synthesis in ‘Whangkeumbae’ Pear (Pyrus pyrifolia)Fruit
I Introduction
II Materials and Methods
III Results
IV Discussion
Chapter 7 Effect of Preharvest Bagging on Fruit Storage Characteristics of ‘Chili’ Pear Fruit
I Introduction
II Materials and Methods
III Results and Discussion
IV Conclusions
Chapter 8 The Gene Cloning and Analysis of Expression Pattern of Endoβ1,4glucanase Gene during ‘Chili’ Pear Fruit Development and Maturation
I Introduction
II Results and Analysis
III Discussion
IV Conclusions
Chapter 9 Expression of Two Endo1,4βglucanase Genes during Fruit Ripening and Softening of Two Pear Varieties
I Introduction
II Materials and Methods
III Results
IV Discussion
References