Comparison of the Effects of H_2O_2 and Salicylic Acid on Alternative Respiratory Pathway in Aged Potato Tuber Slices

The influences of exogenous H 2O 2 and salicylic acid (SA) treatments on the alternative respiratory pathway (ARP) in aged potato (Solanum tuberosum L.) tuber slices were compared. The results showed that both H 2O 2(5.0 mmol/L) and SA (0.1 mmol/L) treatments had a significant inducing effect on ARP capacity (V alt ) and its ratio to total respiration (V alt /V t) in potato slices aged for 24 h. With a monoclonal antibody against the alternative oxidase (AOX), Western blotting results showed that both H 2O 2 and SA treatments increased the AOX expression levels in aged potato tuber slices. However, the results of oxygen isotope discrimination experiments showed that H 2O 2 had no influence on the in vivo ARP activity (ρV alt ) and its contribution to V t(expressed as ρV alt /V t) in potato slices aged for 24 h, but SA had a significant influence on the ρV alt and ρV alt /V t values of the aged potato tuber slices. These results indicate that there are differences between the effects of H 2O 2 and SA on ARP in plant tissues. Both of them possess the ability to induce ARP capacity through inducing AOX expression. However, SA can simultaneously stimulate the operation of ARP, but H 2O 2 can not.

Potato/Maize intercropping reduces infestation of potato tuber moth, Phthorimaea operculella(Zeller) by the enhancement of natural enemies

The potato tuber moth(PTM),Phthorimaea operculella(Zeller),is one of the most economically significant insect pests for potato in both field and storage worldwide.To evaluate the infestation,reduction of potato yield and the control efficacy for PTM,field tests were conducted in two seasons by intercropping of potato as the host plant with maize as a non-host plant of PTM.Three intercropping patterns were tested,which were 2 rows of potatoes with either 2,3,or 4 rows of maize(abbreviated 2 P:2 M,2 P:3 M,and 2 P:4 M),and the monocropped potato as the control,2 rows of potatoes,without maize,(abbreviated 2 P:0 M).Results showed that the population and infestation of PTM in the 2 P:3 M intercropping pattern was significantly lower than those in 2 P:2 M,2 P:4 M and the monocropping pattern of 2 P:0 M,due to the enhancement of natural enemies.Cumulative mines and tunneling in potato leaves in 2 P:3 M intercropping were significantly lower than those in 2 P:2 M and 2 P:4 M patterns.The population of parasitoids and the parasitism rate of PTM in intercropping pattern of 2 P:3 M were significantly higher than that in intercropping pattern of 2 P:2 M,2 P:4 M and monocropping pattern of 2 P:0 M.We conclude that the potato intercropped with maize reduced the adult and larva populations,and reduced the damage from PTM by enhancing the number of parasitoids and the level of parasitism.The greatest population density of parasitoids and parasitism rate were in the intercropping pattern of 2 rows of potatoes with 3 rows of maize.These data indicate that the host/non-host intercropping patterns can be used as a biological control tactic against PTM by enhancing the density of natural enemies in the agro-ecosystems.

Screening of Extraction Methods for Protein from Potato Tubers

[Objectives]This study was conducted to screen different extraction methods for protein from potato tubers.[Methods]The bud eye,lateral and pith parts of Qingshu 168 and Kexin 1 were used as test materials,and were extracted by acetone extraction,trichloroacetic acid(TCA)extraction,salt extraction,alcohol extraction and phenol extraction,respectively.The protein contents of different parts were determined by spectrophotometry.A 2-factor randomized block design was used to study the effects of varieties,extraction methods,sampling parts and combinations of different factors on protein content.[Results]The protein contents of different varieties were different,and Qingshu 168 was significantly higher than Kexin 1(P<0.05),reaching 128.0 mg/L.The protein contents obtained by different extraction methods were different.Acetone extraction,salt extraction and TCA extraction showed no significant differences in the protein content,but they were significantly higher than phenol extraction and alcohol extraction(P<0.05).The protein contents obtained by the former three were in the range of153.3-159.7 mg/L.The protein content in the bud eye part of potato tubers was significantly higher than those in the lateral and pith parts(P<0.05),reaching140.7 mg/L.There were significant differences among different combinations of varieties,extraction methods and sampling parts(P<0.05).The comprehensive comparison showed that the salt extraction method was suitable for the bud eye part of Qingshu 168,and the TCA extraction method was suitable for the bud eye part of Kexin No.1.[Conclusions]This study provides a reference for potato protein extraction and further research.

Development and Evaluation of Codon-modified cryV Constructs in Cultivated Potato(Solanum tuberosum L.) for Control of Potato Tuber Moth

A cryV gene,specifically toxic to Lepidoptera and Coleoptera,was incorporated into binary vectors with different promoters and the presence or absence of the β-glucuronidase(gus) reporter gene.These constructs were integrated into potato cv.Spunta by Agrobacterium tumefaciens-mediated transformation.Highest expression of cryV gene,determined by mRNA levels and insect mortality,was obtained using the CaMV 35S promoter without the gus gene configuration.Detached leaf and tuber bioassays showed a mortality rate of up to 83% and 100%,respectively,for potato tuber moth(Phthorimaea operculella Zeller) in the transgenic lines.Our results demonstrated that the presence of the gus gene negatively affects the expression level of the cryV gene.Bt expression was also facilitated by using the(ocs)3 mas super promoter,whereas the Bt expression regulated by the patatin promoter(tuber-specific) was too low to have any effect upon the mortality of potato tuber moth.These results represent significant improvement in the level of host plant resistance for the control of potato tuber moth via Bt transgenes.

Effect of Inorganic and Organic Fertilizers on Growth and Yield of Two Industrial Potato Varieties (Asterix and Courage) in Bangladesh

Potato is one of the most important vegetable crops, which contributes more than half of the total vegetable production in Bangladesh. Four field experiments were conducted in two different locations in Bangladesh to develop integrated nutrient management practices to produce quality potato seed in industrial processing varieties Asterix and Courage. For the inorganic trial, Factorial Randomized Complete Block Design (RCBD) including 2 potato varieties, 5 treatments with 4 replications, and in the organic fertilizer trial, Factorial RCBD including 2 potato varieties, 6 treatments with 4 replications were used. In the inorganic fertilizer trail, the highest yield was obtained in the variety Asterix due to Nitrogen, Phosphorus, Potassium, and Sulfur (NPKS) plus Magnesium treated plot in Domar BADC farm and due to NPKS plus Boron, Zinc, and Magnesium treated plots in Kashimpur Farm. In the case of variety Courage, the highest yield was found in the treatment of NPKS plus Zinc in Domar BADC farm while in Kashimpur farm, NPKS plus Mg treated plots had the highest yield of potato variety-Courage. In the organic fertilizer trail, the highest tuber yield per hill was obtained by applying the government-approved commercial brand Northern organic fertilizer in variety Asterix and by organic fertilizer brand Chook Chook in variety Courage. Parameters such as days to tuber initiation, number of stems per hill, plant height, and number of tubers per hill were found statistically different among the treatments and between the two varieties. Treatments namely Northern organic fertilizer and Cowdung combined with mustard oil cake performed better considering standard grade tuber yield (grade A and B) compared to other treatments. Hence, the combination of NPKS MgZn and either Northern organic or Chook Chook or Cowdung plus mustard oil cake could be used to grow the varieties Asterix and Courage.

Impact of soil compaction on the engineering properties of potato tubers

A study on a 30 hm2 field was conducted to assess the variability in soil compaction and to investigate its effect on the engineering properties of potato tubers in terms of tuber shape and key dimensions(length,width and thickness)and resistance to penetration,rupture and shear forces.Three soil compaction levels were spatially correlated with the engineering properties of potato tubers through linear regression and ANOVA test.The three compaction levels included a low level(C1)ranging between 1.2-1.9 MPa,a medium level(C2)with compaction levels between 2.0-2.3 MPa and a high level(C3)ranging between 2.4-2.9 MPa.Results revealed that there were no significant changes in the key tuber dimensions corresponding to the variability in soil compaction.However,inverse linear relationships were observed between soil compaction and the key tuber dimensions with R2 values of 77%,97%and 96%for length,width and thickness,respectively.Similarly,the soil compaction was shown to have no effect on the tuber resistance to compression and shear force.In contrast,the tuber resistance to penetration was significantly affected by soil compaction(p>F=0.0012).

A Transgenic Study on Affecting Potato Tuber Yield by Expressing the Rice Sucrose Transporter Genes OsSUT5Z and OsSUT2M

In many plants, sucrose transporters are essential for both sucrose exports from sources and imports into sinks, indicating a function in assimilate partitioning. To investigate whether sucrose transporters can improve the yield of starch plant, potato plants （Solanum tuberosum L. cv. D^siree） were transformed with cDNAs of the rice sucrose transporter genes OsSUT5Z and OsSUT2M under the control of a tuber- specific, class-I patatin promoter. Compared to the controls, the average fructose content of OsSUTSZ transgenic tubers significantly increased. However, the content of the sugars and starch in the OsSUT2M transgenic potato tubers showed no obvious difference. Correspondingly, the average tuber yield, average number of tubers per plant and average weight of single tuber showed no significant difference in OsSUT2M transgenic tubers with controls. In the OsSUTSZ transgenic lines, the average tuber yield per plant was 1.9-fold higher than the controls, and the average number of tubers per plant increased by more than 10 tubers on average, whereas the average weight of a single tuber did not increase significantly. These results suggested that the average number of tubers per plant showed more contribution than the average weight of a single tuber to the tuber yield per plant.

Endogenous Hormone Concentration in Developing Tuberous Roots of Different Sweet Potato Genotypes

A field trial was conducted to investigate the changes of endogenous hormone concentration （EHC） during formation and thickening of tuberous roots in sweet potato （Ipomoea batatas L.） of different genotypes： Xushu 18, Minamiyutaka, and L trifida-K123. The results of this study suggested that the concentrations of zeatin riboside （ZR）, dihydro-zeatin riboside （DHZR）, abscisic acid （ABA）, indole-3-acetic acid （IAA）, and isopentenyl-adenine （IPA） of Xushu 18 and Minamiyutaka were significantly higher than those of I. trifida-K123. Dry tuberous root yields were positively correlated with the concentration of ABA, ZR, and DHZR at 1 or 5% significant level, but were not obviously correlated with the concentrations of IAA, IPA, and GA4. The concentrations of ABA, ZR and DHZR played very important roles in the tuberous root formation and thickening in sweet potato. The concentrations of ZR, DHZR, ABA, and IAA in the upper or inner portion of tuberous roots were significantly higher than those toward the end of the root or its outer portion. Meanwhile, EHC of large-sized tuberous roots were significantly higher than those of medium- or small-sized tubers during the early thickening period. In the rapid thickening period of tuberous roots, EHC of medium-sized tubers were the highest, However, at the late-thickening period, EHC of small-sized tubers ranked the highest.

Expression of auxin synthesis gene tms1 under control of tuber-specific promoter enhances potato tuberization in vitro

Phytohormones, auxins in particular, play an important role in plant development and productivity. Earlier data showed positive impact of exogenous auxin on potato (Solanum tuberosum L.) tuberization. The aim of this study was to generate potato plants with increased auxin level predominantly in tubers. To this end, a pBinB33-tms1 vector was constructed harboring the Agrobacterium auxin biosynthesis gene tms1 fused to tuber-specific promoter of the class I patatin gene (B33-promoter) of potato. Among numerous independently generated B33:tms1 lines, those without visible differences from control were selected for detailed studies. In the majority of transgenic lines, tms1 gene transcription was detected, mostly in tubers rather than in shoots. Indoleacetic acid (IAA) content in tubers and the auxin tuber-to-shoot ratio were increased in tms1-expressing transformants. The organ-specific increase in auxin synthesis in B33:tms1-transformants accelerated and intensified the process of tuber formation, reduced the dose of carbohydrate supply required for in vitro tuberization, and decreased the photoperiodic dependence of tuber initiation. Overall, a positive correlation was observed between tms1 expression, IAA content in tubers, and stimulation of tuber formation. The revealed properties of B33:tms1 transformants imply an important role for auxin in potato tuberization and offer prospects to magnify potato productivity by a moderate organ-specific enhancement of auxin content.

Mapping QTL underlying tuber starch content and plant maturity in tetraploid potato

Tuber starch content and plant maturity are two important agronomic traits of potato. To investigate the complex genetic basis of these traits in the cultivated potato, as well as the relationship between them, we developed a linkage map in a tetraploid population of 192 clones derived from the cross Longshu 8 × Zaodabai and mapped quantitative trait loci(QTL) for tuber starch content and plant maturity using data collected in three diverse environments over two years. We detected eleven QTL for tuber starch content distributed on seven chromosomes, of which four, on chromosomes I, II, and VIII, were expressed in at least three environments. For plant maturity, we identified six QTL on chromosomes II, IV,V, VII, and XI, one of which, on chromosome V, showed LOD peaks ranging from 45.2 to 62.5 cM and explained 21.6%–26.6% of phenotypic variation was expressed in five of the six environments. Because the reproducible QTL for plant maturity and tuber starch content mapped to different chromosomes and neither overlapping QTL, nor any genetic interaction between QTL were detected, we infer that tuber starch content and plant maturity are controlled by independent genetic loci. This inference supports the prospect of breeding potato for both early maturity and high starch content.

Nitrogen Nutrition Index and Its Relationship with N Use Efficiency, Tuber Yield, Radiation Use Effi ciency, and Leaf Parameters in Potatoes

Knowledge about crop growth processes in relation to N limitation is necessary to optimize N management in farming system. Plant-based diagnostic method, for instance nitrogen nutrition index （NNI） were used to determine the crop nitrogen status. This study determines the relationship of NNI with agronomic nitrogen use efficiency （AEN）, tuber yield, radiation use efficiency （RUE） and leaf parameters including leaf area index （LAI）, areal leaf N content （NJ and leaf N concentration （N0. Potatoes were grown in field at three N levels： no N （N 1）, 150 kg N ha^-1 （N2）, 300 kg N ha^-1 （N3）. N deficiency was quantified by NNI and RUE was generally calculated by estimating of the light absorbance on leaf area. NNI was used to evaluate the N effect on tuber yield, RUE, LAI, NAL, and NL. The results showed that NNI was negatively correlated with AEN, N deficiencies （NNI〈 1） which occurred for N 1 and N2 significantly reduced LAI, NL and tuber yield; whereas the N deficiencies had a relative small effect on NAL and RUE. To remove any effect other than N on these parameters, the actual ratio to maximum values were calculated for each developmental linear relationships were obtained between NNI and tuber RUE to NNI. stage of potatoes. When the NNI ranged from 0.4 to 1, positive yield, LAI, NL, while a nonlinear regression fitted the response of

Improved Nucleic Acid Spot Hybridization Technique for Detection of Potato Spindle Tuber Viroid(PSTVd)

Potato spindle tuber viroid(PSTVd)disease is one of the major diseases that threatens potato production.Therefore,an advanced,rapid and sensitive detection technology is needed to detect the disease for better control.In order to establish an easier nucleic acid spot hybridization(NASH)method,some studies were tried as the followings:(1)the pre-hybridization step of nucleic acid spot hybridization(NASH)was omitted compared with ordinary way;(2)RNA extraction(phenol extraction and Ames buffer extraction)methods were compared;(3)fixed RNA by UV lamp and oven compared with UV cross-linker;(4)hybridized the RNA in shaking incubator and so on.The results showed that RNA extracted by Ames buffer was more effective than by the phenol extraction method.Besides,the result of hybridization without pre-hybridization step was better than that with 1.5 h of pre-hybridization.The more important discovery was that the shaking incubator could replace the hybridization oven and the ordinary UV lamp could replace the UV cross-linker.After a long term repeated research and testing,a new hybridization system that could rapidly detect the PSTVd by improved NASH technique merely using common instruments and equipment was established.

Detection of Potato Spindle Tuber Viroid, and Its Impact on Growth, Production of Tomatoes in Greenhouse

The viability of most tomato varieties cultivated in Libya have been tested to infect with potato spindle tuber viroid/potatoes （PSTVd） and its impact on growth and production of some of these varieties, which were mechanically inoculated with Libyan isolate of viroid PSTVd as follows： Vlkato, Sankarh, Lebda, Jasmine, Kenza and Hana. The percent of incidence were 95.95%, 90%, 90.80%, 80% and 20%, respectively. The following varieties have been contagious mechanically with viroid of PSTVd： Vlkato, zahra, Toria, Lebda, Hoda, Farwa, Alkaraz, Naziha, Rim Star and Kartika. The percent of incidence were 95.95%, 85%, 85.80%, 80%, 70.40%, 0.0%, 0.0%, respectively. The varied symptoms of wrinkle, twist, warp, swell the veins of the leaves, dark brown spots formation and a large yellow spots turned into white patches. Also the effect of the Egyptian isolate viroid PSTVd in the growth and production of varieties Jasmine, Lebda, Soberhalim, and treasure No. 185 had been studied, as the average rates of decline in the production of the fruits tomatoes/tomato 43.4% and 17% length of plants, and in the fresh weight and dry root of the sum of 35% and 37% respictively.

The Key Factors Affecting Tuber Development of Potato in vitro and the Relation with Protein Fractions

According to previous analysis, some properties bounding up with tuber yield were investigated. The results showed that tuber average weight, plastid Mg2 + -ATPase activity, plastid Ca2 + -ATPase activity, mitochondria Mg2 + -ATPase activity, total soluble protein content, tuber average diameter, and Q-enzyme activity were important factors determining the tuber yield. The linear regression equation was:Y = 0.5211 + 0.0595X(1)+0.8389X(2) +0.0882X(3) -0.0073X(4) +0.1449X(5) +0.3510X(6) +0.0031X(7) -0.00003X(8) + 0.3412X(9) + 0.0127X(10) + 0.2904X(ll) + 0.0570X(12) + 0.0159X(13) + 0.3585X(14) + 0.0134X(15) - 0.1012X(16). At the same time, the relation between several important properties and soluble protein fractions were analyzed.

Management of Grass and Broadleaf Weeds in Processing Potatoes (Solanum tuberosum L.) with Clomazone, in the Argentinian Pampas

Weed competition in the potato crop could cause up to a 95% yield reduction depending on the variety, the weed species and the competition period. In this work the effect of Clomazone (Command 36 CS®), when applied alone or in combination with Metribuzin (Sencorex® 48) upon grass and broad-leaved weeds was assessed. The work was carried out under the environmental conditions of the Argentinian Pampas, where close to 50% of the potatoes produced in the country are grown. The field trial was performed during the spring-summer crop, season 2008/09, with cv. Innovator, in a completely randomized design of the following treatments: (a) control, without weed control;(b) Clomazone 1.6 l·ha-1;(c) Clomazone 2.0 l·ha-1;(d) Clomazone 1 l·ha-1 + Metribuzin 0.75 l·ha-1;(e) Clomazone 1.6 l·ha-1 + Metribuzin 0.5 l·ha-1;and (f) Metribuzin 1.35 l·ha-1. Treatment effectiveness (TE), crop competition level (CCL) and weed suppression index (WSI) were assessed at 38, 53 and 72 days after planting (DAP), while yield and quality were also evaluated, following industry protocols. In those treatments were Clomazone was used alone, at 2 l·ha-1, or combined (Clomazone 1 l·ha-1 + Metribuzin 0.75 l·ha-1), a higher yield was observed. Besides, a high correlation between TE, WSI and tuber yield was also achieved. Clomazone improved TE, CCL and WSI, which was not only reflected in higher tuber yields, but also on better tuber quality.

Effects of Agrobacterial<i>rol</i>-Genes on the Thermodynamic and Structural Features of Starches Extracted from Potato Microtubers

Wild-type potato (Solanum tuberosum L.) plants and their transformants harboring agrobacterial rolB or rolC genes under control of the patatin class I promoter were cultured in vitro. These plants were used as a source of single-node stem cuttings. The structure of native starch in tubers formed on cuttings was determined using methods of X-ray scattering and differential scanning microcalorimetry (DSC). It was found that in starch from tubers of rolB plants the melting temperature of crystalline lamella was lower and their thickness was less than that in wild-type potato. In tubers of rolC plants starch differed from starch in wild-type plants by a higher melting temperature, reduced melting enthalpy, and a greater thickness of crystalline lamellae. The melting of starch from tubers of rolC plants proceeded as the melting of two independent crystalline structures with melting temperatures of 338.0°K and 342.8°K. Overall data show that starches of different structure can be obtained by using transgenic approach.

Study on Mutagenic Effect of Cobalt-60 Irradiation on Potato

[Objective] This study aimed to investigate the mutagenic effect of cobalt- 60 irradiation on potato. [Method] Potato tubers of Favorita and Zhongshu No.3 were irradiated with 5, 10, 20, 30, 50 and 70 Gy of cobalt-60 γ-ray respectively, to explore the mutagenic effect of different doses of γ-ray heavy ion irradiation on potato. [Result] The results showed that the emergence rate, seedling rate, plant growth, yield and commodity of potato varied after irradiated with different doses of cobalt-60 γ-ray; 10Gy of cobalt-60 irradiation played a positive effect on the growth and development of potato, while high doses played a negative effect on the growth and development of potato. After cobalt-60 irradiation, the botanical traits of M1 gen- eration varied greatly, resulting in a number of beneficial mutation traits; some traits of M2 and M3 generations became stably inherited. [Conclusion] Cobalt-60 irradiation breeding is conducive to the variety improvement and germplasm innovation as an effective means of genetic improvement for potato.

Micro-Tuber Production in Diploid and Tetraploid Potato after Gamma Irradiation of in Vitro Cuttings for Mutation Induction

Micro-tubers are important propagules in potato breeding and potato production, and they are also dormant and easily transported and therefore good targets for mutation induction in potato mutation breeding. A prerequisite for mutation breeding is to determine optimal mutation treatments. Therefore, radio-sensitivity tests of a tetraploid and a diploid potato to gamma irradiation were undertaken. Effects of different gamma sources on radio-activity were also studied. In vitro potato cuttings were gamma irradiated using a wide dose range (0, 3, 6, 9, 12, 15 and 20 Gy). The irradiated cuttings were then cultured to induce micro-tubers directly in vitro. Micro-tuber morphotypes were assessed after irradiation of cuttings using three gamma sources with emission activities of 1.8, 7.07 and 139 Gy/min. The diploid species (Solanum verrucosum) was more radio-sensitive than the tetraploid cultivar Desirée (Solanum tuberosum). Gamma dose rates had significant influences on subsequent micro-tuber production at various mutant generations. Effects included reductions in the number, size and weight of micro-tubers produced. Gamma dose was more lethal for the diploid potato genotype and micro-tubers produced were small compared to those produced by the tetraploid genotype after irradiation. Different treatments are recommended for diploid and tetraploid potato irradiation in producing large mutant micro-tuber populations. The mutant micro-tuber populations may then be screened for interesting mutations/trait for both genetics and plant breeding purposes.

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。

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。