Inheritance of steroidal glycoalkaloids in potato tuber flesh

Potato (Solanum tuberosum L.) is the third most important food crop worldwide after wheat and rice in terms of human consumption. A critical domestication trait for potato was the decrease of toxic steroidal glycoalkaloids (SGAs) in tuber flesh. Here, we used a diploid F2 segregating population derived from a cross between S. tuberosum and the wild potato species Solanum chacoense to map the quantitative trait loci (QTLs) associated with the regulation of SGAs content in tuber flesh. In a three-year study, we identified two QTLs on chromosomes 2 and 8 affecting SGAs content in tuber flesh. The QTL on chromosome 8 harbors 38 genes that are co-expressed with the GLYCOALKALOID METABOLISM genes. These findings lay the foundation for exploiting the genes controlling SGAs content in tuber flesh and they provide a theoretical basis for the use of wild germplasm in potato breeding.

高效液相色谱法测定马铃薯薯肉中类胡萝卜素

本实验研究了用高效液相色谱法测定马铃薯薯肉中叶黄素和玉米黄素。采用丙酮:石油醚(1:1,含0.1%BHT)混合液直接提取,用ZOBAXC18(4.6×250mm,5μm)色谱柱,乙腈:甲醇:二氯甲烷(75:20:5,含0.1%BHT)为流动相,进样量为5μl,流速为1ml/min,柱温为25℃,在450nm下检测类胡萝卜素。研究结果表明,该法可以快速、准确地分离测定马铃薯薯肉中叶黄素和玉米黄素的含量,具有良好的线性(相关系数分别为0.9997和0.9987)和重复性,叶黄素和玉米黄素回收率分别达到92.87%和95.68%。而且本方法可有效防止类胡萝卜素氧化,因而非常适用于大批量样品的分析检测。

2种薯肉色甘薯对亚硒酸盐的吸收累积特性

【目的】分析2种薯肉色甘薯对亚硒酸盐的吸收累积效应,为探索安全高效的富硒甘薯生产技术和促进广西富硒甘薯产业健康发展提供参考依据。【方法】以橘黄色薯肉的桂薯10号和紫色薯肉的桂紫薯1号为试验材料,测定盆栽土壤中不同浓度(0、0.20、0.40和0.80 mg/kg)亚硒酸盐处理[分别设为Se 0(对照)、Se 0.2、Se 0.4和Se 0.8处理]甘薯植株的农艺性状、薯块产量和品质,分析亚硒酸盐在不同薯肉色甘薯品种各器官中的累积和分配规律。【结果】施用0.20和0.40 mg/kg亚硒酸盐均可显著提高甘薯的单株鲜薯产量(P<0.05,下同);施用不同浓度亚硒酸盐对同种薯肉色甘薯植株的蔓长、分枝数和单株结薯数及薯块的可溶性糖、蛋白和胡萝卜素含量均无显著影响(P>0.05);Se 0.2、Se 0.4和Se 0.8处理桂紫薯1号的原花青素含量均低于对照,其中Se 0.8处理显著低于对照23.08%;根、茎、薯块和叶片的硒含量在植株不同生长发育时期均高于对照;2种薯肉色甘薯各器官的硒累积量和分配率排序均为薯块>根>叶>茎;薯块中的硒形态均为有机硒,未检测到四价硒和六价硒,其中,硒代胱氨酸含量占有机态硒含量的比例明显高于甲基硒代半胱氨酸含量,桂薯10号薯块的硒代胱氨酸含量占有机硒含量的比例随着外源亚硒酸盐浓度的增加而升高,而桂紫薯1号薯块的硒代胱氨酸含量占有机硒含量的比例随着外源亚硒酸盐浓度的增加而降低。【结论】桂薯10号和桂紫薯1号中的硒均为有机态的硒代胱氨酸和甲基硒代半胱氨酸,其中硒代胱氨酸含量明显高于甲基硒代半胱氨酸含量;在土壤中施用0.20和0.40 mg/kg亚硒酸盐甘薯薯块的产量较高,施用0.80 mg/kg亚硒酸盐桂薯10号薯块的硒代胱氨酸含量占有机态硒含量的比例高于桂紫薯1号,生产实践中可根据甘薯品种特性施用适宜浓度的外源硒。

Genome-wide Analysis of MYB Gene Family in Potato Provides Insights into Tissue-specific Regulation of Anthocyanin Biosynthesis

The MYB transcription factor is one of the largest gene families in plants,playing an important role in regulating plant growth,development,response to stress,senescence,and especially the anthocyanin biosynthesis.In this study,A total of 217 MYB genes,including 901R-MYBs,124 R2R3-MYBs,and 3 R1R2R3-MYBs have been identified from the potato genome.The 1R-MYB and R2R3-MYB family members could be divided into 20 and 35 subgroups respectively.Analysis of gene structure and protein motifs revealed that members within the same subgroup presented similar exon/intron and motif organization,further supporting the results of phylogenetic analysis.Potato is an ideal plant to reveal the tissue-specific anthocyanins biosynthesis regulated by MYB,as the anthocyanins could be accumulated in different tissues,showing colorful phenotypes.Five pairs of colored and colorless tissues,stigma,petal,stem,leaf,and tuber flesh,were applied to the transcriptomic analysis.A total of 70 MYB genes were found to be differentially expressed between colored and colorless tissues,and these differentially expressed genes were suspected to regulate the biosynthesis of anthocyanin of different tissues.Co-expression analysis identified numerous potential interactive regulators of anthocyanins biosynthesis,involving 39 MYBs,24 bHLHs,2 WD-repeats,and 29 biosynthesis genes.Genome-wide association study(GWAS)of tuber flesh color revealed amajor signal at the end of Chromosome 10,which was co-localized with reported I gene(StMYB88),controlling tuber peel color.Analyses of DEGs(Differentially Expression Genes)revealed that both StMYB88 and StMYB89 were closely related to regulating anthocyanin biosynthesis of tuber flesh.This work offers a comprehensive overview of the MYB family in potato and will lay a foundation for the functional validation of these genes in the tissue-specific regulation of anthocyanin biosynthesis.

不同肉色甘薯交互嫁接后块根干物质积累研究

本文通过对"徐薯18","渝苏162","渝薯99","渝紫263"、"渝苏紫43"等3种不同肉色类型的5个不同品种的交互嫁接,设置25个嫁接组合和双重对照,分析嫁接后不同肉色甘薯在生长过程中的块根干物率和产量的变化情况。结果表明,①嫁接后,块根干物率和产量的变化受到砧木、接穗、生长期及其交互作用的共同影响;光合产物在地上部和地下部的分配与块根干物质产量的积累成极显著相关;②与未嫁接的植株比较,嫁接对大多数嫁接组合的光合产物向下运输有阻碍作用,对少数特定组合在特定的生长时期有显著促进作用;③与相同品种嫁接的植株比较,同一肉色类型的甘薯砧木对其它2种肉色类型接穗对响应能力不一致,同一肉色类型甘薯接穗对其它2种肉色类型砧木对影响能力也是不一致的。

几个因素对紫肉甘薯食用品质的影响

通过DPS逐步回归分析来研究鲜薯产量、薯块的干物质、花色苷、可溶性糖的含量等因素对紫肉甘薯食用品质的影响.结果表明:薯块干物质含量与食用品质中的水分、质地显著正相关,花色苷含量与食用品质中的水分、质地呈显著负相关,而鲜薯产量和可溶性糖含量与食用品质无显著相关性.质地与影响食用品质的风味、纤维、一般评价等评定指标显著正相关,而水分只与一般评价指标显著正相关.因此,主要通过对质地评定指标的作用,薯块的干物质和花色苷含量是影响紫肉甘薯食用品质的主要因素.

马铃薯块茎不同部位的矿质元素分布规律

为了进一步研究马铃薯块茎不同部位的矿质元素分布规律,提升马铃薯的综合利用价值,采用火焰原子吸收光谱法和酸溶—火焰光度法等国标方法,分别测定了3个马铃薯品种块茎芽眼、薯皮和薯肉共9个部位的干物质和7种矿物质含量。结果表明:采用削皮刀手工去皮时,除芽眼外削掉薯皮占薯块重量的比值平均为8.83%;3个马铃薯品种块茎不同部位的干物质在鲜薯中的含量为107.89~236.39 g/kg,K、Ca、Mg、Zn、Mn、Cu、Fe含量分别为2.32~6.50 g/kg、11.36~237.41 mg/kg、38.56~105.79 mg/kg、3.03~16.46 mg/kg、0.94~3.32 mg/kg、1.12~2.22 mg/kg、6.43~51.31 mg/kg,其中K、Ca、Mg、Mn、Fe含量均表现为薯皮>芽眼>薯肉,Zn和干物质含量均表现为芽眼>薯肉>薯皮,Cu含量表现为芽眼>薯皮>薯肉;不同矿质K、Ca、Mg、Zn、Mn、Cu、Fe元素之间存在一定的正向相关性,除脐部薯皮矿质元素含量与顶部和环髓区薯肉的相关性不显著外,其余不同部位的矿质K、Ca、Mg、Zn、Mn、Cu、Fe元素含量之间相关性均为显著或极显著。马铃薯块茎的薯皮和芽眼周围比薯肉部位含有更丰富的矿质元素,其矿质元素的综合利用更值得研究。

彩色马铃薯块茎形成和贮藏过程中花色苷变化及抗氧化活性分析

以不同彩色马铃薯基因型为材料,对块茎形成和贮藏过程中花色苷的种类及含量变化进行了研究。结果表明,在块茎发育过程中,不同马铃薯基因型块茎中花色苷出现的时间与含量多少各有差异,颜色较深的基因型花色苷达到最高含量的时间先于颜色浅的基因型,且不同组分的出现与累积变化规律基本上与花色苷合成的先后顺序一致;在常温和低温贮藏过程中,花色苷含量均呈下降趋势,但下降比例并无明显差异。抗氧化活性测定表明,几种彩色马铃薯基因型块茎均有一定的清除DPPH·和ABTS+能力以及Fe3+还原能力,但不同基因型间抗氧化能力存在差异。