Key Technology for Virus-free Seed Potatoes Pre-elite Breeding

[Objectives]To establish a breeding system for pre-elite seed potatoes.[Methods]Shoot-tip seedlings were cultured with different medium,and then transplanted in different substrates.They were sprayed with nutrient solutions of different formulas.Potato minitubers were induced.[Results]The medium of MS+2.0 mg/L 6-BA,1.0 mg/L NAA+3%sugar was preferable for potato shoot tip culture.After virus detection,the virus-free potato seedlings were propagated.The medium composed of vermiculite,peat and perlite(1∶3∶1)was recommended for transplanting potato tissue culture seedlings in greenhouse.The three-dimensional spray method was used to produce pre-elite seed potatoes.The full-amount MS nutrient solution could increase the tuber number per plant to 55.Induction of minitubers is a better breeding technology for pre-elite seed potatoes.The optimal medium screened for induction of potato minitubers was MS+(5-7)mg/L 6-BA,with a dark culture duration of about 20 d.[Conclusions]The breeding technology established is suitable for the two-season cultivation areas in Zaozhuang.

In Vitro Synthetic Seed Production of Potato under Different Fungicide Levels and Storage Intervals

Potato propagation through tubers and seed is an inefficient way of propagation thus we propose an alternative method in this study which is in vitro propagation.Plantlets were raised from True Potato Seeds(TPS)in test tubes containing 10 mL of Murashige Skoog(MS)medium.Subculturing was done after every 21 days and after four subsequent subculturing,when there was an adequate quantity of stock material,uninodal cuttings of about 3-4 mm in length were prepared from in vitro proliferated potato plants by excising leaves of 1-2 mm on each side of the node.Prepared uninodal cuttings were cultured on 1/2 strength MS medium for root primordia development.The selected uninodal cuttings with root primordia were encapsulated with sodium alginate solution(3.5%(w/v)),mixed with 1.25%charcoal and different concentration of fungicide(thiophanate methyl,sigma)to enhance the viability percentage of synthetic seed.Furthermore,these encapsulated uninodal cuttings were subjected to different storage intervals to check maximum storage.Results showed that optimum dose for fungicide is 150 mg/L as it resulted in good viability percentage,shoot number,shoot length,rooting percentage,root number,root length and ideal for bead formation with sodium alginate.Similarly,results revealed that encapsulated uninodal cuttings can be stored at a temperature of 4℃ up to 45 days with a survival rate of 63.33%.Encapsulated uninodal cutting stored for 60 days showed a poor viability percentage of about 43.03%.It can be concluded that optimum dose of 150 mg/L with storage time of 45 days should be used to get a better outcome for synthetic potato seed production.

Study on Virus-free Breeding Technology of Potato Microtuber

It is the simplest,fastest and effective way to improve the yield level of potato by selecting high quality virus-free seed potato for field production and maintaining the original characters of virus-free minituber. Microtuber is featured by small volume,no pathogen,convenient storage and transportation,which can be induced in summer with high temperature and humidity,and overcome a series of problems such as poor survival rate of transplanted test-tube plantlets,and easy pollution of cutting tips. Therefore,it can replace conventional test-tube plantlets directly for reproduction. Meantime,if minitubers are sown ahead of time using cold frame,the growth stage of potato minituber will avoid the occurrence period of aphids. The use of gauze cover for insect prevention has good effect on maintaining the excellent characters of microtuber. The yield and quality of virus-free potato are greatly improved by means of virus-free culture of shoot tip seedlings,subculture propagation of virus-free seedlings,induction of microtubers by dark culture,cultivation of breeder’s seeds in greenhouse and screenhouse to preserve the characters of potato.

Correlations between delayed fluorescence of chlorophyll, metabolism and yield of plants. III. Influence of viral infection on field plants and new technology of clone selection of virus-free planting potato

At the end of potato plants vegetation virus in-fection induced both decrease in maximum amplitude of delayed fluorescence maximal amplitude and increase half time of its decrease, as well as reduction in the amount of stems, plants’ height and assimilation area surface, yield, acceleration of plants development and their early die-off. The differences of DF pa-rameters and yields between strongly and weakly infected plants increase in case of a combined virus infection. In industrial test of the selection of virus-free planting potato by the use of DF parameter, a rise in the yield and de-crease degree of viral infection of crops was obtained.

Design and Experiment of four Lines Trailed Potato Fertilization Seeder

In order to solve the problems which are widespread in potato seeding planter, such as lower operating efficiency, unideal performance index, higher replay rate and leakage rate and uneven spacing sowing in seeding operating, a trailed potato fertilization seeder was designed. The key components of the special structure had been got through the description of the structure and working principle of the whole machine. A crossing seed-taken technology along with the vibration component was adopted to achieve precision seeding. The results showed in the feld test of the machine： all the performance indexes of the machine met the agronomic requirement of potato planting; the multiple and missing index were low; it completed the ditching, fertilizing, seeding as well as ridging in one planting process; its operation effciency was high and the stability was good. This design of the trailed potato fertilization seeder provided a reference for the development of large traction-type potato seeding machine.

Genetic Variance Estimates in Heterogeneous Potato Populations Propagated from True Potato Seed(TPS)

Twenty nine cross populations developed according to line × tester mating design along with their twelve parents raised from true potato seeds, were used to study variability and correlation for seven characters. The range of variation for all the characters were found to be wide and pronounced which indicated that characters were quantitative in nature and were under polygenic control. For all the characters, greater portion of the total δ2p was mostly contributed by the δ2g. Among the seven characters, tuber weight per plant showed the highest δ2g, PCV, GCV, H2b, GA and expected GA%. On the other hand, dry matter contents (%) showed the lowest H2b. Phenotypic and genotypic correlation coefficients of plant height with no. of tubers per plant and tuber weight per plant; no. of branches per plant with no. of tubers per plant and tuber weight per plant were found to be significant and positive.

Potato Seed Supply, Marketing and Production Constraints in Eritrea

Potato is an important vegetable crop in Eritrea contributing significantly to food security. Despite its importance, however, production and thus supply of the crop in the market are limited. The current study is designed to understand the seed supply system, marketing out lets and major production constraints. The survey was conducted in the two main potato producing Zobas of the country (Zoba Maekel and Zoba Debub). Qualitative and quantitative data was generated using focus group discussion (PRA) and semi structured questionnaire, respectively. A total of 20 villages were visited and 138 farmers were interviewed. The finding revealed that there is no standard seed supply system thus majority (91.3%) of the growers purchase seed from open market with a limited supply from the Ministry of Agriculture. Furthermore, about 63% of the farmers from Zoba Maekel reserve their own seed for the next cycle compared to 53.6% from Zoba Debub. It was noted that the Tsaeda embaba variety grows predominantly in the country owing to its yield and resistance. Majority of the growers rely on tuber colour and shape for variety identification, thus over 76% prefer the round shaped and white coloured variety. The potential marketing outlets include wholesale, retailer and direct to consumers. Majority (78.3%) of the interviewed growers indicated that large portion of their produce is marketed via wholesaler followed by retailers (27.5%). Main production limiting constraints are identified as low input supplies, availability and cost of clean seeds, pest pressure while huge market demand and access to transportation are considered as potentials encouraging grower. It is, therefore, recommended that an immediate action to establish sustainable seed supply system is taken into consideration in line with a regular extension service to provide technical advice to growers.

Design and experiment of conical diversion virus-free potato minituber precision seed-metering device

In order to accelerate the development of sowing mechanization of virus-free potato minituber,a conical diversion virus-free potato minituber precision seed-metering Device was designed according to the structural characteristics and agronomic requirements of virus-free potato minituber.The device is mainly composed of conical turntable,transmission shaft,outer baffle of seed-metering Device,baffle,seed outlet,seed cleaning device,type hole,etc.The working principle of conical diversion precision seed-metering device for virus-free potato minituber was expounded,and the stress analysis of virus-free potato minituber in each region was carried out.By EDEM discrete element simulation software,the structure of the type hole is optimized to determine the optimal structure of the type hole and according to the physical characteristics of virus-free potato minituber,the single factor experiments of the effects of length of type hole,cone disc speed and cone disc angle on seed filling performance were completed.The orthogonal regression test was carried out with the length of type hole,cone disc speed,and cone disc angle as the test objects,and the leakage rate and qualified rate as the response indexes.The regression models of leakage rate,replay rate,and qualified rate were established,and the parameters of the regression model were optimized.The optimal parameter combination is that the length of type hole is 33.61 mm,the cone disc speed is 6.35 r/min,and the cone disc angle is 26.59°.Bench test was carried out under the optimal conditions,the leakage rate was 3.80%,the replay rate was 0.80%,and the qualified rate was 95.40%,which was basically consistent with the prediction results of the regression model,and met the requirements of precision sowing of virus-free potato minituber.

基于电驱动的智能播补一体化马铃薯播种机设计研究

马铃薯是我国重要的粮食和经济作物,在西南丘陵山区受限于地势条件,现有马铃薯播种机在作业时均不同程度的存在株距误差大、漏播及重播率高、土壤条件适应性差的问题。为此,设计了以AT89S51单片机为运算核心的播补薯一体机,主要由漏播监测、播补薯、株距控制模块组成。其中,漏播监测模块主要由红外线发生和接收装置组成,播补薯模块主要由步进电机驱动的取种勺根据系统命令执行指定作业,株距控制模块则通过设定的株距指令控制电机的转速及修正;同时,以步进电机作为动力取代了传统的地轮驱动以减小株距误差,步进电机驱动的单链取种勺集成播补薯功能于一体。试验表明:机具作业行走速度在0.6~1m/s时,补薯成功率为73%~81%,总播种成功率为97%~98%,播种株距误差为2.52%~4.83%,整体播种性能完全满足马铃薯播种农艺要求。

不同保鲜袋包装对雾培马铃薯微型种薯贮藏保鲜效果的影响

为了明确不同保鲜袋包装对雾培马铃薯微型种薯贮藏保鲜效果的影响,以大西洋雾培微型种薯为试材,通过测定种薯块茎贮藏期间的失重率、发芽率和腐烂率及其相关生理指标等,探究4种保鲜袋对微型种薯的贮藏保鲜效果。结果表明,在(20±1)℃下,与普通网袋(CK)相比,普通A膜袋、纳米保鲜袋、核桃保鲜袋、蒜薹保鲜袋等4种保鲜袋均能有效改善微型种薯的贮藏保鲜效果,其中以核桃保鲜袋和纳米保鲜袋对微型种薯的贮藏保鲜效果较佳。这2种保鲜袋包装均能够明显降低微型种薯的失重率,且以纳米保鲜袋包装微型种薯的腐烂率最低,贮藏84 d,核桃保鲜袋和纳米保鲜袋包装微型种薯的失重率分别较CK降低73.20%、63.62%,核桃保鲜袋包装微型种薯的腐烂率较CK升高21.43%,纳米保鲜袋包装微型种薯的腐烂率较CK降低31.25%;抑制相对电导率和丙二醛(MDA)含量的上升速度,减少细胞膜的受损程度,贮藏70 d,核桃保鲜袋和纳米保鲜袋包装微型种薯的MDA含量分别较CK降低23.26%、13.95%;同时,还可促进过氧化物酶(POD)、过氧化氢酶(CAT)及超氧化物歧化酶(SOD)活性的提高,减少氧自由基的伤害,并能够正常发芽,对雾培微型种薯具有良好的贮藏保鲜效果。综合考虑,建议在雾培微型种薯贮藏期间采用纳米保鲜袋包装。

4行气吸式马铃薯原原种精量播种机设计

马铃薯原原种的繁育最早由人工种植,其生产成本高,不利于规模化生产。基于原原种的种植农艺要求、种子物理性状和耕作种床条件等情况,进行了4行气吸式马铃薯原原种精量播种机的研究设计。通过台架和田间试验得到,该播种机的操作性能、播种精度和质量都满足种植的农艺要求,实现了马铃薯原原种机械化精量播种作业。

马铃薯切块薯种取种勺设计与仿真优化

马铃薯切块播种是节约用种成本、打破薯种休眠的有效途径,针对马铃薯播种机传统圆形取种勺对切块薯种适应性较差,导致漏播率高,播种合格率低的问题,对马铃薯播种机取种勺进行了设计与仿真优化。在测定薯种力学特性参数的基础上,利用EDEM软件,选取Hertz-Mindlin接触模型,构建了切块薯种离散元模型。通过对切块薯种取种充种状态进行分析,以传统圆形取种勺为基础,设计了一种切口式马铃薯播种机取种勺,并确定了影响取种效果的主要因素。以切口圆心角、切口深度和切口个数为试验因素,以取种成功率、重种率和空种率为评价指标,开展三因素三水平虚拟仿真正交试验。正交试验结果表明:切口式取种勺取种能力明显优于传统圆形取种勺,当切口圆心角为60°,切口深度为15 mm、切口数量为3个时,其取种效果最优。利用优化后的取种勺进行切块薯种播种验证试验,结果表明:播种取种成功率为82.2%,重种率为7.1%,空种率为10.7%,相比于传统圆形种勺,其重种率降低约12个百分点,取种成功率提升约12.5个百分点。

基于激光三维重建的种薯芽眼识别方法研究

种薯芽眼的准确识别是实现智能切块的重要前提。为解决种薯芽眼机器视觉识别易出现误判和不易获取芽眼三维位置信息而导致切块不均匀的问题,提出一种基于激光三维重建的种薯芽眼识别方法。确定点云获取过程中ROI区域消除采集过程中背景的影响,通过工业相机与线激光器相配合连续采集移动种薯的激光光条图像获取其点云数据;根据点云密度去除随机噪声和裙边噪声,提高点云质量,降低芽眼误判率。采用体素滤波算法稀疏点云,提高识别效率;通过对种薯表面任意点的局部邻域进行平面拟合后获取点云法向量,构建加权协方差矩阵参数化种薯表面点云,根据矩阵特征值大小设定的动态阈值对种薯表面点云进行初步筛选,得到种薯芽眼判别的候选点,采用欧式聚类算法获取候选点的点云簇,选取每个点云簇中最大特征值点为关键点,利用计算关键点和邻域内其他点构成的中心线连线向量与法向量夹角余弦值对关键点再次筛选,最终确定种薯各个芽眼位置。试验结果表明,芽眼识别率为95.13%,芽眼误识别率为4.87%,可为马铃薯种薯智能化切块时芽眼识别提供参考。

双螺旋振动式马铃薯供种装置离散元仿真及优化

对丘陵山区马铃薯切块种薯播种机械化程度低的问题,提出一种双螺旋振动式供种装置,通过EDEM仿真试验对切块薯在料斗内输送过程进行研究,并设计正交试验通过响应面法对切块薯振动式供种装置关键参数进行优化,提高供种速率。通过理论分析和仿真试验表明,影响切块薯物料输送效率的因素包括振动装置工作电压、单个轨道螺距以及底面倾角,其中工作电压和单个轨道螺距通过改变物料在螺旋轨道上的运动速度来调整输送速率,而底面倾角通过改变物料分散进入螺旋轨道的速度来提高。通过正交试验和响应面法,得到较优参数:工作电压200 V,单个轨道螺距186.626 mm,料斗底面倾角为5.075°时,输送速率最高为214粒/min,满足马铃薯切块薯排种器供种需求。该研究为后续丘陵山区马铃薯精量播种技术提供理论参考。

不同排种量对甘薯采苗量和薯苗质量的影响

为了明确排种量对甘薯采苗量和薯苗质量的影响,以商薯19(S19)和烟薯25(Y25)为试验材料,采用平排的方式,设置10、15、20、25 kg/m^(2)4个排种量,其中25 kg/m^(2)为常规排种量,从采苗量、薯苗质量、薯苗生长特性和薯苗群内环境条件(温湿度和光照强度)等方面进行分析。结果表明:S19和Y25的采苗量均随排种量的增加表现先升高后降低的趋势,以20 kg/m^(2)排种量处理最高,分别为2124株/m^(2)和986株/m^(2),较10、15、25 kg/m^(2)处理分别显著增加107.4%、19.1%、10.1%和100.4%、45.4%、8.6%;Y25叶片净光合速率、茎部剪切力和拉伸力也均以20 kg/m^(2)排种量处理最高,分别较25 kg/m^(2)排种量处理显著增加16.54%、25.4%、44.5%;S19和Y25薯苗壮弱比、茎部机械力、茎部木质素含量及叶片、叶柄和茎干率也都是20 kg/m^(2)排种量处理显著高于25 kg/m^(2)排种量处理。S19和Y25薯苗群体中光照强度随排种量的增加而降低,20 kg/m^(2)排种量处理分别较25 kg/m^(2)排种量处理显著增加20.1%和18.2%;相对湿度则随排种量的增加而增加,20 kg/m^(2)排种量处理分别较25 kg/m^(2)排种量处理显著降低12.2%和4.7%;薯苗群体温度均表现为先下降后上升,S19品种20 kg/m^(2)排种量处理温度较25 kg/m^(2)排种量处理显著降低5.1%。综上,适宜排种量可形成合理的薯苗群体结构,改善群体内部小气候,提高光合性能和茎部机械力,促进薯苗干物质积累,显著提高采苗量和薯苗质量,平排条件下以采苗量为目的的最佳排种量为20 kg/m^(2)。

雾培条件下3个马铃薯新品种(系)的农艺性状及其微型种薯的繁育评价

【目的】探明雾培对马铃薯农艺性状及微型种薯繁育的影响,为脱毒微型种薯的繁育提供参考。【方法】以广西地区3个性状优异的马铃薯新品种(桂农薯1号、桂彩薯1号和20号品系)为材料,检测雾培条件下马铃薯的重要农艺性状及微型种薯的产量。【结果】随着雾培时间延长,3个马铃薯品种的茎长、茎粗和节位数等性状均逐渐增加,其中,20号品系的茎长、茎粗、总根数和匍匐茎数量均显著高于桂农薯1号和桂彩薯1号,叶片数和根长小于桂彩薯1号,桂农薯1号仅匍匐茎长度优于其他2个品种;微型种薯产量方面,20号品系的单株种薯平均产量比桂农薯1号和桂彩薯1号分别高29.3%和45.4%,种薯单重比桂农薯1号和桂彩薯1号分别高14.9%和24.6%;SPAD和LAI方面,20号品系在整个测定过程中均比桂农薯1号和桂彩薯1号表现优异。【结论】综合比较3个品种(系)马铃薯在雾培条件下的农艺性状和微型种薯生长情况,20号品系马铃薯更适宜于雾培法进行微型种薯繁育。

植物生长调节剂拌种对马铃薯生长和产量的影响

以云南陆良县召夸镇为试验地点,通过设置寡聚酸碘、5%氨基寡糖素、甲壳寡糖素3种植物生长调节剂6种不同的配置方案,对不同植物生长调节剂配置拌种下马铃薯生长情况和产量指标2个角度进行评估,探究植物生长调节剂拌种对马铃薯生长和产量的影响,以期为马铃薯的科学种植提供试验数据依据。

马铃薯精量排种技术发展现状与展望

中国是马铃薯生产大国,马铃薯种植规模大、范围广。马铃薯种植存在过程繁杂、劳动强度大、效率低等问题,研究马铃薯机械化种植十分重要。目前有多种排种技术应用于马铃薯机械化种植,勺链式排种器结构简单,传动稳定;气吸式排种器能实现精密排种;针刺式排种器对种薯的适应性较好。针对机械化排种过程中的漏播问题,漏播检测与自动补偿技术对于提高马铃薯播种效率具有重要意义。分析了国内外马铃薯精量排种技术的研究现状,比较不同排种器之间的区别,阐述现阶段马铃薯精量排种存在漏播、消耗功率大、对种薯的损伤较大等问题,为马铃薯精量排种技术的研究提供参考。

山西省马铃薯产业发展的现状及建议

总结山西省马铃薯产业发展的现状、优势及限制因素,并提出有针对性的建议,以助力山西省马铃薯产业实现高质量发展。就发展现状而言,山西省马铃薯总产量稳步提升,单产快速增加,耕种收机械化水平提升,品种结构不断完善,产业技术体系基本形成。山西省马铃薯产业发展拥有主要产区布局集中、政府政策大力支持、马铃薯收益相对较高等优势,但也面临马铃薯生产成本上升,脱毒种薯推广缓慢,品种结构仍较单一,储藏设施比较落后以及品牌建设亟待加强等问题。在此基础上,提出山西省马铃薯产业发展的对策建议:落实落细政府支持政策;促进品种多元化、脱毒种薯规模化;推进储藏设施集中化、智能化;通过新媒介加强品牌建设。

Occurrence and molecular characterization of Potato spindle tuber viroid(PSTVd) isolates from potato plants in North China

China is the largest potato producing country worldwide,with this crop representing the fourth largest staple food crop in China.However,the steady presence of Potato spindle tuber viroid（PSTVd） over the past five decades has a significant economic impact on potato production.To determine why PSTVd control measures have been ineffective in China,more than 1 000 seed potatoes collected between 2009 and 2014 were subjected to PSTVd detection at the Supervision and Testing Center for Virus-free Seed Potatoes Quality,Ministry of Agriculture,China.A high PSTVd infection rate（6.5%） was detected among these commercial seed potatoes.Some breeding lines of potato collected from 2012 to 2015 were also tested for PSTVd infection,revealing a high rate of PSTVd contamination in these potato propagation materials.Furthermore,comparison of the full-length sequences of 71 different Chinese PSTVd isolates revealed a total of 74 predominant PSTVd variants,which represented 42 different sequence variants of PSTVd.Comparative sequence analysis revealed 30 novel PSTVd sequence variants specific to China.Comprehensive phylogenetic analysis uncovered a close relationship between the Chinese PSTVd sequence variants and those isolated from Russia.It is worth noting that three intermediate strains and six mild strains were identified among these variants.These results have important implications for explaining the ineffective control of PSTVd in China and thus could serve as a basic reference for designing more effective measures to eliminate PSTVd from China in the future.