旨在探讨、验证优质食用型紫肉甘薯新品种创制的最佳策略,为甘薯高效育种提供借鉴。以来自日本的优质紫肉型甘薯‘川山紫’为母本,以高产、高糖材料‘冀薯6-8’为父本,通过有性杂交、系统选育获得优质食用型紫肉甘薯新品种‘榕紫薯5号’。该品种2011—2013进行多点选拔、品比及鉴定,2014—2015年参加福建省甘薯区试。对‘榕紫薯5号’的形态特征、农艺性状、品质性状、抗病性、生产力、适应性进行了试验研究。结果表明,‘榕紫薯5号’为中晚熟品种,生育期135天,萌芽性好,分枝能力中等,全生育期群体长势强劲,结薯集中。2014—2015年福建省甘薯区域试验平均鲜薯产量30.24 t/hm ²,平均干物率30.12%,平均出粉率19.84%,食味评分81.6分,比对照高1.6分。外观评分81.3分,比对照高1.3分。花青素含量26.95 mg/100 g FW。大中薯率68.7%。省区试综合鉴定结果为：株型中蔓半直立;鲜薯产量、薯干产量和淀粉产量比对照高;干物率和淀粉率与对照相当;食味品质、外观品质均优于对照;抗蔓割病,中抗薯瘟病,耐贮性好,该品种达到食用型甘薯品种审定标准,可作为鲜食及特用薯在中国南方薯区广地域种植。

This study is to investigate and verify the optimum breeding strategy of edible-type sweet potato with purple flesh. A new edible-type sweet potato cultivar with purple flesh and good quality ‘Rongzishu No.5’ was bred from female parent ‘Chuanshanzi’ with purple flesh and good quality from Japan, and male parent ‘Jishu No.6-8’ with high yield and high sugar content by sexual hybridization and systemic selection. The cultivar was selected, compared and identified through multi-spots trial from 2011 to 2013, and tested in Fujian Provincial Sweet Potato Regional Trial from 2014 to 2015. The morphological characteristics, agronomic characteristics, quality characteristics, disease resistance, productivity and adaptability of ‘Rongzishu No.5’ were studied. The results show that ‘Rongzishu No.5’ is a mid-late ripening variety, its growth period is 135 days, it has strong sprouting capacity and medium branching ability, the canopy is steady vigor during the whole growth period and the tuberization is concentrative. In Fujian Provincial Sweet Potato Regional Trial (2014-2015), the average yield of fresh tuberous root of ‘Rongzishu No.5’ was 30.24 t/hm ², the average dry matter rate was 30.12%, the average starch rate was 19.84%, the test value of cooked taste was 81.6 and 1.6 points higher than CK, the test value of extrinsic feature was 81.3 and 1.3 points higher than that of CK. The concentration of anthocyanin was 26.95 mg/100 g FW. The rate of large and medium-sized tuberous root was 68.7%. The results of comprehensive identification in Fujian Provincial Sweet Potato Regional Trial indicate that ‘Rongzishu No.5’ has a semi-erect architecture with medium length vine; the yield of fresh tuberous root, dry tuberous root and starch are higher than those of CK, the dry matter rate and starch rate are equivalent to those of CK, the qualities of cooked taste and extrinsic feature are superior to those of CK. ‘Rongzishu No.5’ has resistance to Fusarium oxysporum and moderate resistance to Ralstonia solanacearum wilt, the storability of tuberous root is fine. The variety meets the approval standard of edible-type sweet potato varieties and could be widely cultured in south China.