Teh Soon Li, Kostick Sarah, Brutcher Lisa, Schonberg Bonnie, Barritt Bruce, Evans Kate
Tree Fruit Research and Extension Center, Washington State University, Wenatchee, WA, United States.
Front Plant Sci. 2021 Oct 18;12:714325. doi: 10.3389/fpls.2021.714325. eCollection 2021.
Washington State University's apple breeding program (WABP) was initiated in 1994 to select new apple cultivars with improved eating quality, appearance, and storability that are suitable for production in the main growing regions of the state. Fruit quality is phenotyped using various instrumental measures, such as penetrometers (texture), titrator (acidity), and refractometer (soluble solids concentration; SSC), as well as sensory assessment. The selection regime of WABP occurs in three sequential phases: phase one (P1)-single, unreplicated seedlings at one site, phase two (P2)-replicated selections at three geographically diverse sites, and phase three (P3)-highly replicated elite selections at one to two grower sites. Most of the data collection of WABP occurs in P2. Knowledge of trends/changes associated with advancing selections is essential for understanding the selection criteria and progress of WABP throughout the changing compositions of advancing and culling selections. For each post-harvest trait, P2 data from harvest years 2005 to 2019 were split across sites, and between selections and reference cultivars (e.g., Cripps Pink, Gala, and Honeycrisp). Means of instrumental crispness (Cn) and inner cortex firmness for the advancing selections increased gradually over this period and were significantly higher than those for cultivars. Means of outer cortex firmness measurements were stable for selections but significantly higher than those for cultivars. The average fruit acidity of selections increased marginally over this period and was higher than that of the cultivars. Meanwhile, the average fruit SSCs of selections and cultivars were statistically indistinguishable. These 15-year trends indicate that WABP has been selecting apples with improved eating quality and storability through increased crispness and inner cortex firmness, respectively.
华盛顿州立大学的苹果育种项目（WABP）始于1994年，旨在选育食用品质、外观和耐贮性更佳的新苹果品种，这些品种适合在该州主要种植区进行生产。果实品质通过多种仪器测量进行表型分析，如硬度计（质地）、滴定仪（酸度）和折射仪（可溶性固形物浓度；SSC），以及感官评估。WABP的选择过程分为三个连续阶段：第一阶段（P1）——在一个地点种植单一、未重复的实生苗；第二阶段（P2）——在三个地理上不同的地点进行重复选择；第三阶段（P3）——在一到两个种植者地点进行高度重复的优良选择。WABP的大部分数据收集发生在P2阶段。了解与选择进展相关的趋势/变化对于理解WABP在不断变化的入选和淘汰选择组成中的选择标准和进展至关重要。对于每个采后性状，2005年至2019年收获年份的P2数据按地点、选择品种和参考品种（如克里普斯粉红、嘎拉和蜜脆）进行划分。在此期间，入选品种的仪器脆度（Cn）和内皮层硬度平均值逐渐增加，且显著高于品种。外皮层硬度测量平均值在选择品种中保持稳定，但显著高于品种。在此期间，选择品种的平均果实酸度略有增加，且高于品种。同时，选择品种和品种的平均果实SSC在统计学上没有差异。这15年的趋势表明，WABP一直在分别通过提高脆度和内皮层硬度来选育食用品质和耐贮性更佳的苹果。
