新品种'华南16号'('SC16')(Manihot esculenta Crantz cv.SC No.16)是以木薯品种'华南8号'('SC8')为母本和引进品种'Q10'(I93/0665)为父本进行人工杂交获得F1杂交种子,经实生苗试验、初级品比、高级品比、区域试验和生产性试验等选育而成.其鲜薯产量在区域试验和生产性试验分别为50.15 t/hm2和45.82 t/hm2,比我国主栽品种'华南205'('SC205')分别增产55.45％和35.85％;块根淀粉率分别为25.42％和26.10％,略低于'SC205'(对照);鲜薯氰苷含量为29.70μg/g,属于甜木薯品种.综合试验结果表明,'华南16号'是1个株型优良、高产,且能够密植与机械化采收的工业用、食用兼饲用的新品种,适宜在我国广西、广东沿海、海南,以及东南亚地区推广种植.

Cassava (Manihot esculenta Crantz) is a major tuberous crop produced worldwide. In this study, we sequenced 158 diverse cassava varieties and identified 349,827 single-nucleotide polymorphisms (SNPs) and indels. In each chromosome, the number of SNPs and the physical length of the respective chromosome were in agreement. Population structure analysis indicated that this panel can be divided into three subgroups. Genetic diversity analysis indicated that the average nucleotide diversity of the panel was 1.21 × 10-4 for all sampled landraces. This average nucleotide diversity was 1.97 × 10-4, 1.01 × 10-4, and 1.89 × 10-4 for subgroups 1, 2, and 3, respectively. Genome-wide linkage disequilibrium (LD) analysis demonstrated that the average LD was about ∼8 kb. We evaluated 158 cassava varieties under 11 different environments. Finally, we identified 36 loci that were related to 11 agronomic traits by genome-wide association analyses. Four loci were associated with two traits, and 62 candidate genes were identified in the peak SNP sites. We found that 40 of these genes showed different expression profiles in different tissues. Of the candidate genes related to storage roots, Manes.13G023300, Manes.16G000800, Manes.02G154700, Manes.02G192500, and Manes.09G099100 had higher expression levels in storage roots than in leaf and stem; on the other hand, of the candidate genes related to leaves, Manes.05G164500, Manes.05G164600, Manes.04G057300, Manes.01G202000, and Manes.03G186500 had higher expression levels in leaves than in storage roots and stem. This study provides basis for research on genetics and the genetic improvement of cassava.

Postharvest physiological deterioration (PPD) is a global challenge in the improvement of cassava value chain. However, how to reduce cassava spoilage and reveal the mechanism of injured cassava storage roots in response to PPD were poorly understood. In the present study, we investigated the activities of antioxidant enzymes of cassava injured storage roots in PPD-susceptible (SC9) and PPD-tolerant (QZ1) genotypes at the time-points from 0h to 120h, and further analyzed their proteomic changes using two-dimensional electrophoresis (2-DE) in combination with MALDI-TOF-MS/MS. Ninety-nine differentially expressed proteins were identified from SC9 and QZ1 genotypes in the pairwise comparison of 24h/0h, 48h/0h, 72h/0h and 96h/0h. Of those proteins were associated with 13 biological functions, in which carbohydrate and energy metabolism related proteins were the biggest amount differential proteins in both genotypes, followed by chaperones, DNA and RNA metabolism, and defense system. We speculated that SOD in combination with CAT activities would be the first line of defense against PPD to support PPD-tolerant cassava varieties. The four hub proteins including CPN60B, LOS2, HSC70-1 and CPN20B, produced from the network of protein-protein interaction, will be the candidate key proteins linked with PPD. This study provides a new clue to improve cassava PPD-tolerant varieties and would be helpful to much better understand the molecular mechanism of PPD of cassava injured storage roots.

木薯是粗生易种的经济作物,耐贫瘠,病虫害少,但这并不意味着粗放的栽培管理方式就能获得高产.选择适当的栽培品种和栽培模式、加强收获及田间生产管理、对病虫害进行及时有效的防治,能够大大提高木薯的产量和经济效益.论述了木薯高效栽培技术的应用及木薯种植综合效益的提升等内容,指出目前我国木薯种植业存在的问题并提出几点建议.

近年来我国在木薯品种引进、良种选育、丰产栽培技术研究等方面取得了较大进展,然而一些高产优质木薯品种的推广现状与木薯产业发展的需要还存在一定的差距.比较分析了我国主要的木薯栽培种在多地区栽培条件下的单产、淀粉含量、干物质含量、氢氰酸含量及抗逆性等状况,并就木薯栽培品种的选择提出几点建议.

To effectively control cassava soil insects,occurrence regularity and control technology of cassava major soil insects grub and Dorysthenes granulosus were studied.The results showed that,one generation of grub occurred at least 1a,its adults often emergenced in 6～8 months and after raining each year in Hainan and Guangxi.The sloping fields,sandy fields,cassava cropping fields,sugarcane crop rotation fields and peanut intercropping fields were infectee more harmful by grub in the condition of high temperature and drought.One generation of D.granulosus occurred at least 2～3 a,its adults often emergenced in 4～6 months and after raining each year in Hainan and Guangxi.The sloping fields,sandy fields,cassava cropping fields,sugarcane crop rotation fields and peanut intercropping fields were suffered more harmful from D.granulosus in the condition of high temperature and drought.When planting,soaking the stems with the water mixture 48% chlorpyrifos EC 1 000 times and 1.8% mixture of abamectin EC 2 000 times after 5-10 min were to improve significantly germination rate,decrease insect-damage rate and increase production rate.Trapping of pits in soil were very effective to grub and D.granulosus."Saochongguang" was not only very effective to control grub and D.granulosus,but also promoted the development of cassava plants and increase production.Furthermore,integrated control technology of soaking the stems,trapping of pits in soil,soil treatment with insecticide and reasonable rotation was very effective to control grub and D.granulosus,insect-damage rate significantly decreased from 45.6% of CK to 4.2% and its production significantly increased from 16.92 ton/ha to 49.96 ton/ha.The results above will be much helpful to sustainable control cassava pests.

6 demonstration bases for the models of cassava intercropped or interplant were built in Wuming County,Guangxi Province,P.R.China in 2009.the analytical results of yield and benefit showed that: compare with single cassava model(CK),water melon,pumpkin,muskmelon or hair melon interplant cassava,and cassava intercropped peanut or soybean improved 6.1%-25.2% cassava fresh root yield than CK;1.6-4.2 times total income of CK;1.7-4.9 times net income of CK.Interplant model of melon were high benefit than the intercropped model of peanut or soybean.Above model were 16 800 hm2 planted area and occupied 60% in whole Wuming county in 2009.

制订广西区武鸣县香瓜、毛节瓜套种木薯的生产技术规程,从选地整地、选择品种、育苗、施肥、定植、盖拱棚、揭膜通风降温、水分管理、引蔓压蔓、整枝留瓜、保花保瓜、防治病虫害等方面对香瓜及毛节瓜栽培管理进行了规范,从选择品种、种茎处理、种植、补苗间苗、中耕除草、追肥、防治木薯朱砂叶螨等环节对套种木薯的栽培管理进行了规范.

According to the research on the preliminary regularity of the red spider mite(Tetranychus cinnabarinus(Boisduval) outbreak on 3 cassava trials,there were different variety,different cultivation,different intercrop or interplant between 2009-2010.Their results showed that 2 critical damage period in whole cassava growing period,the first was on July to August,the second was on November.South China No.cv.SC8 among 3 cassava cultivars was the highest resistant to T.cinnabarinus."Planting-bed+mulching film" and "intercrop short-period crop" systems could reduce the damage of T.cinnabarinus on cassava.

The high yield and high benefit mode of cassava intercropped with peanut or soybean in Wuming County, Guangxi Province is summarized, which will be helpful to promote the extension and application of the mode.

Taking the local variety SC205 as the control,this paper studies the effect of two climatic factors:monthly mean temperature and monthly total precipitation on the yield and the starch content of 22 cassava varieties.Studying the correlation of the climatic factors with the cassava yield and the starch content to find the main climatic factors which affect the cassava yield,so we can regulate the cassava growth rationally,and provide a reference for cassava production.

This article summarized the high-yielding and high-benefit cultivation model of cassava which was interplanted by water melon or pumpkin,based on many years' practice and exploration in Wuming county of Guangxi.The economic benefit of interplanting water melon and cassava was 210% higher than that of only planting cassava,and the economic benefit of interplanting pumpkin and cassava was 160% higher than that of only planting cassava.

The relationship of different planting methods and cassava yield was studied by complete random method in this experiment.On the same fertilizer standards,compared with conventional planting method,the two planting methods of which level cutting seed-stem in plastic film mulched furrow field or level cutting seed-stem in open furrow field showed remarkable yield increase effects on cassava,the cassava yield increased by 469.9 kg/667 m2 and 367.2 kg/667 m2 respectively,and the yield increasing rate was 23.66% and 18.49% respectively.

Using method of random group (zone)of two factors and four levels among different years and places to study the relationship between planting density,fertilizer application amount and the yield of Huanan No.5. The result shows that when selecting planting density as 550～700 seedling / 667m2,applying the amount of N 3.9kg / 667m2,P2O5 2.0kg / 667m2,K2O 7.8 kg / 667m2,the highest yield can be achieved.

Starch properties of cassava root are a major factor for food and industrial value. The starch properties of 79 cassava varieties/clones were subject to detection, such as fresh root starch content, starch moisture content, amylase content, amylopetin content, peak viscosity, gelatinization temperature, paste transparency, Engler viscosity, and diameter and surface area of starch grain. These 79 cassava varieties/clones showed highly different starch properties which were also correlated with each other. All the cassava varieties/clones were subject to comprehensive analysis by using principle component analysis, and the analysis indicated that the cassava varieties/clones E169, C766, E1424, E339, R72, E217, E344, E232, E316 and Guire 3 had optimum starch processing characteristics, and hence are better varieties/clones for processing in downstream sector.

2000～2001年武鸣县承担南宁市科委下达的<旱地吨粮田栽培技术试验示范>项目,全县两年累计完成"玉米+玉米"种植模式年产吨粮面积6890亩,平均年亩产1054.7公斤.主要实施如下技术: