遮荫对紫肉甘薯块根鲜质量、花色苷含量及产量的影响

Influence of Shading on Fresh Weight,Anthocyanin Content and Root Tuber Yield of Purple-Fleshed Sweetpotato

以＂渝苏紫43＂等3个品种为材料,采用4种遮荫处理,并于栽后不同时间挖根测定块根鲜质量及花色苷含量,研究遮荫对紫肉甘薯块根鲜质量、花色苷含量及产量的影响.结果表明,不同品种栽后153 d,单层遮荫处理使块根鲜质量降低23.33%~76%,块根花色苷含量提高32.72%~49.07%,块根花色苷产量降低32.74%~66.28%;双层遮荫整体上增强了单层遮荫的效果.因此,紫肉甘薯最适宜净作.单层或双层遮荫时,＂渝苏紫43＂或＂渝紫263＂鲜薯或花色苷产量最高.在＂麦-玉-苕＂耕作制度下,以收获鲜薯为目的,＂渝紫263＂较适与玉米等作物套作,＂渝苏紫43＂次之;以获得花色苷为目的,＂渝苏紫43＂较适,＂渝紫263＂次之.遮荫处理对块根鲜质量和花色苷含量的影响主要表现在生长前期（栽后1~25 d）.

The effects of shading on fresh weight,anthocyanin content and yield of the storage root of three purpled-fleshed sweetpotato varieties,＇Yuzi 263＇,＇Yusuzi 43＇ and ＇Yamagawamurasaki＇,were studied in the present paper.The seedlings of the 3 varieties were treated by four shading levels after transplanting.As was shown by determination made 153 d after transplanting,one-layer shady light condition resulted in an increase in anthocyanin content in the storage roots by 32.72% to 49.07%;however,the fresh weight of the storage roots decreased by 23.33% to 76% and anthocyanin yield in the storage roots was reduced by 32.74% to 66.28%.Two-layer shady light condition enhanced the shading effect of one-layer shady on the whole.So,the sole cropping system was recommended for the cultivation of these purpled-fleshed sweetpotato varieties.The yields of fresh storage root and anthocyanin of ＇Yusuzi 43＇ or ＇Yuzi 263＇ were higher under the light condition of one-layer shady or two-layer shady.Under the wheat-corn-sweetpotato cropping system,＇Yuzi 263＇was the best variety to be intercropped with corn,followed by ＇Yusuzi 43＇ for the purpose of harvesting fresh root tuber;and for the purpose of harvesting anthocyanin,＇Yusuzi 43＇ was the best variety to be intercropped with corn,followed by ＇Yuzi 263＇.The effects of shading on yield of fresh storage root and anthocyanin of sweetpotato mainly occurred in the early growth stage（1 to 25 d after transplanting） of the plants.