Effects of Variation in Activities of Starch-Sugar Metabolic Enzymes on Reducing Sugar Accumulation and Processing Quality of Potato Tubers

The experiment was designed,via storing potato tubers of cv.E-Potatol and E-Potato3 in different temperatures,to explore the variation patterns of reducing sugar(RS)and total sugar(TS)contents and enzyme activities that are involved in the pathway of starch-sugar metabolism aiming at identifying the main factors that influence the chip color.The results showed that low temperature in storage was a main factor that accelerated the accumulation of RS of the stored tubers and a very significant linear relationship existed between RS content and chip color index(CCI)of the tubers.Further analysis elucidated that when tubers stored at 4℃,the activities of ADP glucose pyrophosphorylase(AGPase),UDP glucose pyrophosphorylase(UGPase)and sucrose synthase(SuSy)were negatively exponential to the RS content significantly while that of acid invertase and alkaline invertase was significantly linear to RS content.It suggested that these enzymes could play main roles in the cold sweetening of potato tubers through regulating starch-sugar metabolism.     

应用生命表进行马铃薯粘腺毛品系对桃蚜抗性的分析

桃蚜(Myzus persicae)有翅型和无翅型所产后代生活在粘腺毛马铃薯杂交后代D888-4、MH_4-5盆栽植株上的存活率、生长历期与生殖力均显著地低于感性对照品种Superior植株。在适温(22—15℃)或高温(33—18℃)下的Superior植株上,有翅型后代的r_m均大于无翅型的后代。在D888-4和MH_4-5上,两蚜型后代的r_m均接近或等于零。     

施锌对马铃薯产量和品质的影响

在大田条件下，将硫酸锌用于马铃薯栽培，结果表明：适量的施锌可使马铃薯产量和品质均有所提高，而过高施用不仅不会提高，反而会使其产量和品质有所下降。     

Improved climate control for potato stores by fuzzy controllers

The main tasks for climate controllers in potato bulk stores are to keep the storage climate in an appropriate condition for quality conservation. To avoid extra energy costs by using cooling systems the internal climate of potato bulk stores is controlled with outdoor air. A conventionally designed controller is difficult to adapt for an optimal climate control to reduce quality loss. However, a controller designed with fuzzy logic is found as advantageous for adapting control parameters to improve the control process. A test stand is built to ventilate and to control two samples of potato bulks simultaneously with the same outdoor weather conditions for comparisons. Several experiments were carried out to compare climate controllers with different control algorithms, i.e. conventional to a different conventional and conventional to fuzzy.     

马铃薯光合速率、单株叶面积与产量的相关性研究

通过不同品系马铃薯光合速率、单株叶面积和产量的测定,建立块茎产量(y)与光合速率与单株叶面积之积(x)的直线回归方程y=-18.9689 2.778383x,回归系数b=2.778383大于0,且和0的差异达极显著,证明了马铃薯产量y随光合速率与单株叶面积之积x的增大而增加,两者成正相关关系。因此,光合速率与单株叶面积之积可以作为评价马铃薯产量高低的一个重要标准。     

茄链格孢菌侵染马铃薯叶片过程的细胞学观察

采用光学显微镜和电镜技术系统研究了茄链格孢菌对马铃薯叶片的侵染过程及超微结构特征。结果表明：接种2 h后,分生孢子开始萌发,分生孢子各个位置都可萌发产生芽管|接种6 h后,菌丝顶端出现附着孢|接种8 h后,菌丝从细胞间凹陷处直接侵入感病品种东农303叶片表皮细胞内|接种24 h后,受侵染寄主细胞中的菌丝向相邻细胞扩展蔓延,感病品种细胞内含物及各类细胞器基本完全消解。在抗病品种克新1号上,茄链格孢菌的侵染情况与感病品种基本一致,但发生时间明显较感病品种推迟,寄主细胞内的菌丝数量明显少于感病品种|并且在接种24 h后出现细胞壁加厚的防卫反应,在感病品种上没有观察到防卫反应现象。说明抗病品种对茄链格孢菌具有一定的抗侵入和抗扩展能力。     

Influence of agricultural soils on the growth and reproduction of the bio-indicator Folsomia candida

Soil organisms have been recommended as bio-indicators of soil quality due to their sensitivity to anthropogenic influences and their high degree of site-specificity. The objectives of this study were to determine if the relationship between the soil Collembola, Folsomia candida, and forest soil could be extended to other soils and, if not, to determine the relationship between its life parameters and soils from the different phases of an agricultural rotation sequence. A comparison of growth, reproduction and survival of 1 day old neonates and 10 day old juveniles subjected to a series of different soils (composted manure, pasture soil, forest soil, sand alone, and sand supplemented with yeast) established that the association between F. candida and forest soil quality cannot be automatically transferred to soils from other ecosystems. The test also showed that neonate (1 d) individuals were more sensitive to the different soil treatments than 10 d old juveniles and should be used in future tests. On this basis, neonate F. candida individuals were used to determine if the species could be employed to characterize the agricultural soils from the different phases of an organic or conventional rotation sequence. Results demonstrated that changes in body growth and reproduction constituted suitable criteria to characterize the soil quality of these different phases. The research required to develop these results as a standard bio-indicator test of agricultural soil quality is discussed.     

武都冬播地膜马铃薯生产的气象条件分析

通过对武都县2 0 0 0 - 2 0 0 3年冬播地膜马铃薯的试验资料进行统计计算,分析研究了冬播地膜马铃薯生长发育、产量品质及提前上市与气象条件的关系,提出了适宜播种期及高产稳产的对策和措施     

Diversity of Nordic Landrace Potatoes (<Emphasis Type="Italic">Solanum tuberosum</Emphasis> L.) Revealed by AFLPs and Morphological Characters

The management of genebank collections of cultivated potato is costly due to the need for in vitro maintenance and virus eradication. Therefore, it is important to set up conservation strategies, which prevent duplicates entering the collections. In this study, 32 Nordic potato landraces were studied for 57 morphological traits and analysed for amplified fragment length polymorphism (AFLP). Most landraces could be distinguished based on the morphological characters, except five accessions. Using five primer combinations to generate 114 reproducible AFLPs, of which 63 (55%) were polymorphic, the five morphologically indistinguishable accessions were placed into two groups with identical AFLP patterns, suggesting that some of the accessions were redundant for long-term preservation. The AFLP data showed that the Nordic collection of potato landraces is composed of genetically different clones, and morphological analysis revealed a wide range of variability. This variability seems to be distributed randomly over the Nordic region since the cluster analysis based on AFLPs and morphological traits revealed no grouping based on the country of origin. Principal component analysis suggests that fewer morphological traits than used in this study will be sufficient to discriminate between different genotypes of cultivated potato (Solanum tuberosum L.). Future possibilities for rationalising potato collections are discussed.     

平衡施肥对马铃薯产量及品质的影响

通过平衡施肥对马铃薯产量和品质影响的研究,结果表明:在当地条件下,马铃薯最佳经济施肥量为N141 15kg/hm2,P2O5104 55kg/hm2,K2O198 90kg/hm2,施用比例1 0 74 1 41,最佳产量31845 30kg/hm2,施肥利润3306 90元/hm2,投产比1 3 63。采用平衡施肥能增加马铃薯产量,降低薯块硝酸盐和还原糖含量,并能增加淀粉含量,从而提高马铃薯产品品质,增加效益。马铃薯硝酸盐含量随氮肥施用量增加而增加,施用磷钾肥能明显降低硝酸盐含量。我区马铃薯生产重金属污染均未超标,符合国家食品卫生标准。