Xiao Guilin, Huang Wei, Cao Hongju, Tu Wei, Wang Haibo, Zheng Xueao, Liu Jun, Song Botao, Xie Conghua
Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture, Wuhan, China.
National Center for Vegetable Improvement (Central China), Wuhan, China.
Front Plant Sci. 2018 Mar 9;9:315. doi: 10.3389/fpls.2018.00315. eCollection 2018.
Cold-induced sweetening (CIS) caused by reducing sugar (RS) accumulation during storage in low temperature in potato tubers is a critical factor influencing the quality of fried potato products. The reconditioning (REC) by arising storage temperature is a common measure to lower down RS. However, both CIS and REC are genotype-dependent and the genetic basis remains uncertain. In the present study, with a diploid potato population with broad genetic background, four reproducible QTL of CIS and two of REC were resolved on chromosomes 5, 6, and 7 of the CIS-sensitive parent and chromosomes 5 and 11 of the CIS-resistant parent, respectively, implying that these two traits may be genetically independent. This hypothesis was also supported by the colocalization of two functional genes, a starch synthesis gene mapped in QTL CIS_E_07-1 and a starch hydrolysis gene colocated with QTL REC_B_05-1. The cumulative effects of identified QTL were proved to contribute largely and stably to CIS and REC and confirmed with a natural population composed of a range of cultivars and breeding lines. The present research identified reproducible QTL for CIS and REC of potato in diverse conditions and elucidated for the first time their cumulative genetic effects, which provides theoretical bases and applicable means for tuber quality improvement.
马铃薯块茎在低温贮藏期间因还原糖（RS）积累导致的冷诱导糖化（CIS）是影响油炸马铃薯制品品质的关键因素。通过提高贮藏温度进行再处理（REC）是降低RS的常用措施。然而，CIS和REC都依赖于基因型，其遗传基础仍不明确。在本研究中，利用一个具有广泛遗传背景的二倍体马铃薯群体，在CIS敏感亲本的第5、6和7号染色体以及CIS抗性亲本的第5和11号染色体上分别解析出4个可重复的CIS QTL和2个REC QTL，这意味着这两个性状可能在遗传上是独立的。这一假设也得到了两个功能基因共定位的支持，一个淀粉合成基因定位于QTL CIS_E_07-1，一个淀粉水解基因与QTL REC_B_05-1共定位。已证实所鉴定QTL的累积效应在很大程度上稳定地影响CIS和REC，并在由一系列品种和育种系组成的自然群体中得到了验证。本研究在不同条件下鉴定出了马铃薯CIS和REC的可重复QTL，并首次阐明了它们的累积遗传效应，为改善块茎品质提供了理论依据和实用方法。
