通过田间调查及生理生化测试,分析比较了紫甘薯浙紫薯1号野生型及其芽变突变体植株的植物学特征、光合特性、农艺性状、产量及块根品质的差异.结果表明:与野生型相比,突变体茎粗加大,茎长和节间长度显著变短,生长势旺盛;野生型茎和根系为紫色,突变体茎和根系颜色分别为绿色和白色;突变体叶片净光合速率高于野生型;突变体单株结薯数减少,单株产量和单位面积产量显著增加;野生型薯皮、薯肉均为紫色,其花青素含量分别为666.0、536.7 mg/kg,突变体薯皮和薯肉颜色分别为白色和黄色,其花青素含量分别为15.3、11.2 mg/kg,显著低于野生型;突变体块根干物质含量和淀粉含量高于野生型,块根蛋白质含量显著低于野生型,块根食味品质评分为8.9分,显著高于野生型,味粉甜,有板栗香味,粗纤维较少.

In various plant species, many transcription factors (TFs), such as MYB, bHLH, and WD40, have been identified as regulators of anthocyanin biosynthesis in underground organs. However, the regulatory elements of anthocyanin biosynthesis in the tuberous roots of sweet potato have not been elucidated yet. Here, we selected the purple-fleshed sweet potato cultivar "Zhezi1" (ZZ(P)) and its spontaneous yellow-fleshed mutant "Xinli" (XLY) to investigate the regulatory mechanism of the anthocyanin biosynthesis in the tuberous roots of sweet potato. By analyzing the IbMYB1 genotype in ZZ(P) and XLY, we found that the IbMYB1-2, a MYB TF involved in anthocyanin biosynthesis, was missing in the XLY genome, which might lead to an extreme decrease in anthocyanins in XLY. A comparative transcriptome analysis of ZZ(P) and XLY was conducted to find the TFs involved in anthocyanin biosynthesis in ZZ(P) and XLY. The anthocyanin structural genes were significantly enriched among the differentially expressed genes. Moreover, one MYB activator (IbMYB1), one bHLH (IbbHLH2), three WRKY activator candidates (IbWRKY21, IbWRKY24, and IbWRKY44), and two MYB repressors (IbMYB27 and IbMYBx-ZZ) were highly expressed in ZZ(P) accompanied with anthocyanin structural genes. We also tested the expression of these TFs in six purple- and two orange-fleshed sweet potato cultivars. Interestingly, most of these TFs were significantly positively correlated with anthocyanin contents in these cultivars. The function of the anthocyanin biosynthesis repression of IbMYB27 and IbMYBx-ZZ was verified through transient co-transformation with IbMYB1 into tobacco leaves. Further functional verification of the above TFs was conducted by Y2H, BiFC, and dual-luciferase assays. These tests showed that the MYB-bHLH-WD40/MYB-bHLH-WD40-WRKY complex activated the promoter of anthocyanin structural gene IbDFR and promoters for IbWRKY44, IbMYB27, and IbMYBx-ZZ, indicating reinforcement and feedback regulation to maintain the level of anthocyanin accumulation in the tuberous roots of purple-fleshed sweet potato. These results may provide new insights into the regulatory mechanism of anthocyanin biosynthesis and accumulation in underground organs of sweet potatoes.

A preliminary screening for garlic viruses in garlic plants in Hunan, China, using existing monoplex (simplex) reverse transcription-polymerase chain reaction (RT-PCR) procedures detected four viruses/virus groups. These viruses/virus groups were Onion yellow dwarf virus (OYDV), Leek yellow stripe virus (LYSV), Shallot latent virus (SLV) and allexiviruses (e.g., garlic viruses A, B, C, D, E, X). Sequence analysis of the projected allexivirus amplicons revealed the allexivirus in the infected garlic plants was Garlic virus D (GarV-D), which shared 92–97% sequence identities with various isolates from the world. A multiplex RT-PCR (mRT-PCR) was therefore developed to simultaneously detect and differentiate the four viruses/virus groups. To achieve this, four primer pairs targeting allexiviruses, OYDV, LYSV and SLV were designed. The anticipated amplicon sizes are 183 bp (allexiviruses), 265 bp (OYDV), 404 bp (LYSV) and 592 bp (SLV), respectively. All primer pairs produced virus-specific fragments in both simplex and multiplex formats, thus confirming the efficacy of the newly developed mRT-PCR for detection of these viruses. The mRT-PCR further was evaluated by applying it to garlic plant samples collected in two geographic locations in Hunan. Allexiviruses, OYDV, LYSV and SLV were detected in 50.9, 40.3, 28.3 and 58.5% of leaf samples, respectively; and mixed infections with two or more viruses accounted for 54% of the garlic samples. The results obtained by mRT-PCR were confirmed by simplex RT-PCR assays. In conclusion, this newly developed mRT-PCR provides a rapid, sensitive and reliable method for the detection and identification of major garlic viruses.

The virus disease is one of the most damaging diseases in pepper, which affects the yield and quality of pepper. Researches on the virus species, virus biological characteristics, detection methods and control methods of pepper virus disease are summarized in this article. Researches that should be studied thoroughly are previewed. Studies show that more than forty kinds of virus have been found in pepper, which can affect the yield and quality of pepper. TMV and CMV are main virus species of pepper, PVY and BBWV are receiving more and more attention in recent years. The detection methods of pepper viral diseases are also increasingly mature. Breeding for disease resistance, agronomic practices and chemical control methods can play a role in the prevention and treatment of viral diseases. It is significant to establish rapid and effective detection methods and innovate virus disease control methods for the improvement of the yield and quality of pepper.

Potato is the fourth most important food crops, with advantages such as high-yielding and adaptability. However, it is easy to damage by soil-borne diseases under continuous potato cropping. Researches on the soil-borne potato pathogens, symptoms, distribution, and effects of biotic and abiotic factors on the occurrence and development of soil-borne potato diseases and methods of control diseases were reviewed in this article. The emphasis of future research work was prospected.

综述了近年来国内外马铃薯帚顶病毒(PMTV)所取得的研究进展；简述了PMTV的分布与传播、分子特征、病理特征、致病机理及其检测方法,认为PMTV主要出现在气温冷凉的高纬度、高海拔地区的马铃薯上,能通过种薯和粉痂菌传播,诱导马铃薯块茎发生环状坏死;分析了该病毒的特殊性及防治的难点;认为今后要深入研究粉痂菌、马铃薯、PMTV三者之间的相互作用,挖掘PMTV抗性基因,开展马铃薯抗PMTV育种,建立快速准确的PMTV检测方法,探讨同时防治粉痂病和PMTV的途径.

儿童室外活动游戏场地是儿童学习成长的一种方式，也是儿童生活中必不可少的一部分，它有助于儿童智力的成长，自身潜能的开发和对社会适应能力的提高。本文希望通过对长沙市儿童室外活动场地的调查与分析，以晓园公园和烈士公园为例，在对其存在的问题总结的基础上，在整体环境、安全性、自然性、景观要素设计四个方面提出建议，对儿童室外活动场地的设计进行初探，使长沙市公园儿童室外游戏活动场地能为儿童的社会教育、环境教育等提供较好的帮助。

There is abundance natural,safe and non-toxic anthocyanin in tuberous roots of purple sweet potato,which providing mighty anti-oxidation and anti-mutation,as well as the effect of hypoglycemic,protecting liver and anti hypertension.The article summarized the research results in China and abroad about the components and construction of anthocyanin in purple sweet potato,as well as the structural genes and regulatory genes effecting anthocyanin biosynthesis.Then,the key points in further researches were prospected.

马铃薯帚顶病毒主要分布在温度较为寒冷的地区，对马铃薯危害严重，不仅造成马铃薯减产，而且危害马铃薯块茎，使其丧失商品性。本文从分布与传播、分子特征、病理特征、致病机理及检测方法等方面对近年来国内外有关马铃薯帚顶病毒的研究做出综述，并对今后的研究重点进行了展望。