穿山龙锈病病原生物学研究

穿山龙(Dioscorea nipponica Makino.)锈病是辽宁东部山区穿山龙生产上新流行的重要病害。对穿山龙锈病病原鉴定及生物学特性研究表明,引起该病的病原菌为薯蓣柄锈菌(Puccinia dioscoreae Kom.)。该菌夏孢子适宜萌发温度为10～20℃,适宜萌发pH值为6～8,夏孢子萌发速度慢且萌发率较低,加入糖源能促进夏孢子萌发;冬孢子抗逆性较强,可在田间病残体上越冬。     

5个山药品种资源的农艺性状和营养品质比较

对 4个山药栽培品种太谷山药、铁棍山药、花籽山药、日本白山药和 1个野生山药资源进行了农艺性状调查 ,结果表明 ,花籽山药生长势强 ,产量最高 ;其次是日本白山药 ;太谷山药生长势和产量水平中等 ;嵩县野山药产量水平居中等 ,生长势强 ;铁棍山药生长势较弱 ,产量水平最低。营养品质测定结果表明 ,铁棍山药的可溶性总糖、淀粉、粗蛋白质、必需氨基酸和总氨基酸含量均表现最高 ,分别比其他 4个品种高 12 .8%～ 2 96 .8% ,5 9.7%～ 85 .8% ,5 5 .4 %～ 10 8.7% ,114 .3%～2 0 8.8% ,74 .8%～ 135 .7% ,品质最好 ,且含水量最低 (71.8% ) ;太谷山药的淀粉、粗蛋白质、必需氨基酸和总氨基酸含量略高于日本白山药、花籽山药和嵩县野山药 ,但可溶性总糖含量最低。因此 ,可利用上述品种资源的优良性状 ,采用常规杂交和细胞工程技术 ,对现有的栽培品种进行改良 ,以选育出优质、高产、抗病的山药新品种。     

山药真空干燥工艺的研究

为了研究在真空干燥条件下山药片的干燥特性,进而为其真空干燥确定适宜的工艺参数,选用3种真空度0.05、0.06和0.07 MPa,在3种干燥温度45、50和60℃条件下对鲜山药片进行真空干燥试验,测定不同干燥工艺条件下山药片的干燥特性,并进行复水比较试验.试验结果表明,山药片真空干燥适宜工艺条件为0.06 MPa和50℃,复水最佳条件为温度60℃,时间为40 min.     

Morphological Studies on the Mobilization of Reserves in Japanese Yam (Dioscorea japonica Thunb.) Seed Tuber and Eddo (Colocasia esculenta Schott var. antiquorum Hubbard & Rehder) Seed Corm on and after Sprouting

Abstract

We examined the mechanism of reserve mobilization in Japanese yam seed tubers and eddo seed corms on and after sprouting. The decomposition of starch in pith parenchyma cells of Japanese yam tubers and eddo corms progressed from the region distant from vascular bundles to that adjacent to vascular bundles. In eddo corms, the starch also decomposed from the proximal to the distal region adjacent to the sprout or regenerate plant body. In the yam tubers, the decomposition process was similar in the proximal, middle and distal regions. The first step in the reserve mobilization in pith parenchyma cells was the decomposition of the amyloplast envelope. Subsequently, starch granules decomposed. In Japanese yam tubers, the envelope and starch granules started to decompose from the peripheral regions of the amyloplasts. The observation of soluble polysaccharides, which was the decomposition product of starch granules, was made possible by the quick freezing-vacuum freeze-drying method. By this method, we demonstrated that the soluble polysaccharides in the parenchyma cells decomposed and decreased in density. In addition, the mucilage in the mucilage duct started to decompose and decreased in density from the proximal to the distal part of the corm and also from the periphery to the center of the duct. It was shown that not only starch mobilization but also mucilage mobilization mainly supported sprouting and the growth of the regenerate plant body during about the first half of the vegetative stage.     

Non-destructive shoot biomass evaluation using a handheld NDVI sensor for field-grown staking Yam (Dioscorea rotundata Poir.)

ABSTRACT

Crop phenotyping is a key process used to accelerate breeding programs in the era of high-throughput genotyping. However, most rapid phenotyping methods developed to date have focused on major cereals or legumes, and their application to minor crops has been delayed. In this study, we developed a non-destructive method to predict shoot biomass by measuring spectral reflectance in staking yam (Dioscorea rotundata). The normalized difference vegetation index (NDVI) was evaluated using a handheld sensor that was vertically scanned from the top to the bottom of a plant alongside the stake. A linear regression model was constructed to predict shoot biomass through Bayesian analysis using NDVI as a parameter. The model well predicted the observed values of shoot biomass, irrespective of the growth stage and genotypes. Conversely, the model tended to underestimate the shoot biomass when the actual shoot biomass exceeded 150 g plant^?1; this was compensated for when the parameter green area, calculated from plant image, was included in the model. This method reduced the time, cost, effort, and field space needed for shoot biomass evaluation compared with that needed for the sampling method, enabling shoot biomass phenotyping for a large population of plants. A total of 210 cross-populated plants were evaluated, and a correlation analysis was performed between the predicted shoot biomass and tuber yield. In addition to the prediction of tuber yield, this method could also be applied for the evaluation of crop models and stress tolerance, as well as for genetic analyses.     

不同除草剂对豆薯菟丝子的防效与安全性试验

选用7种除草剂对豆薯菟丝子进行茎叶喷雾处理,药后7 d调查菟丝子防除效果和豆薯叶片药害率,药后15 d调查豆薯块茎药害率。结果表明,30%草甘膦异丙胺盐水剂500倍液和1 000倍液对菟丝子茎尖防除效果分别达到95.00%和92.50%,对藤茎的防效分别为85.83%和80.83%,但对寄主植物豆薯叶片药害率分别为49.80%和3.72%;50%乙草胺乳油150倍液对菟丝子茎尖防除效果为83.33%,对藤茎防效为75.83%,对豆薯叶片药害率仅为0.89%;44%氟醚·灭草松水剂250倍液对菟丝子茎尖防除效果为81.67%,对藤茎防效为68.33%,对豆薯叶片无药害影响;其余除草剂虽对豆薯安全性好,但对菟丝子防除效果一般。从菟丝子防除效果和豆薯安全性方面综合考量,50%乙草胺乳油150倍液和44%氟醚·灭草松水剂250倍液可选作本地豆薯菟丝子防控的化学除草剂。     

膨大素对淮山内源激素变化的影响

以桂淮2号薯为试材,研究了结薯初期喷施400 mg/L去豆膨大素对薯块膨大及内源激素变化的影响。结果表明:去豆膨大素处理后能抑制淮山疯长,使得更多的营养物质转向薯块。去豆膨大素处理的GA3含量显著低于对照;ABA含量均显著高于对照;乙烯释放量稍高于对照,IAA含量从第10天开始稍低于对照;ZR含量比对照的稍低,但差异均不显著。从ABA/IAA、GA3/IAA、ZR/IAA和EH/IAA的比值看,ABA/IAA的比值处理比对照显著提高,而GA3/IAA的比值要比对照低。这说明去豆膨大素处理主要通过调节ABA和赤霉素含量能抑制地上部分生长,其次是通过乙烯释放量和生长素含量来达到抑制地上部分生长的效果。     

山药蜂蜜保健果冻制作工艺优化

[目的]优化山药蜂蜜果冻研制的工艺。[方法]以山药为原料,分别用单因素试验和正交试验对果冻制作工艺进行优化。[结果]山药蜂蜜果冻制作的最佳工艺为：山药汁用量为20．00％,混合糖浆（蜂蜜：蔗糖：1：1）用量为15．00％,柠檬酸用量为0．20％．胶凝剂（黄原胶：海藻酸钠=1：3）用量为1．00％。[结论]该研究为研制美味、保健的山药蜂蜜果冻提供了试验依据。     

Yams (Dioscorea spp.) plant size hierarchy and yield variability: Emergence time is critical

Yam crops (Dioscorea spp.) present a very high and unexplained interplant variability which hinders attempts at intensification. This paper aims to characterize the plant-to-plant variability in yield and to identify its underlying causes for the two major yam species (Dioscorea alata and Dioscorea rotundata). Four field experiments were carried out between 2006 and 2009 in Benin. Yams were grown using a traditional cropping method (i.e. in mounds at 0.7 plants m⁻²) without biotic or abiotic stresses. In order to test interplant competition, a low density treatment (0.08 plants m⁻²) was included for D. alata in the 2006 experiment. Throughout four years of experimentation, yields varied from 12 Mg ha⁻¹ to 21 Mg ha⁻¹. Both yam species presented a high interplant coefficient of variation (CV) for tuber yield (42–71%). The unbiased Gini coefficient (G′) was used to measure how steep a hierarchy is in an absolute sense. CV and G′ of individual plant biomass both confirm clear plant size hierarchies from early growth. However, no difference in the CV of plant size and plant tuber yield was observed between high and low plant density. This implies that, despite early interaction between neighbouring plants, competition was not the driving factor controlling plant variability. In fact uneven emergence proved to be the primary cause. Yam emergence takes place over a long period (e.g. it took 51 and 47 days for the 90% central range to emerge for D. alata and D. rotundata, respectively), creating an early inter-plant size hierarchy which later affected tuber production. For both species, plants which emerged early initiated their tuberization earlier in the growing season and reached higher maximum yield regardless of weather conditions (e.g. 1200 and 764 g plant⁻¹ for early-emerging D. alata and D. rotundata plants respectively, and 539 and 281 g plant⁻¹ for late-emerging plants). Plant size hierarchization together with its observed left-skewed distribution, led to reduce total and marketable yield by increasing the proportion of small tubers. These results highlight the need to better understand the underlying mechanisms controlling the yams’ uneven emergence before attempting to improve traditional cropping systems.     

桂淮2号山药(淮山)叶芽营养及可食性分析

对山药新品种桂淮 2号叶芽营养及加工食用性进行研究 ,结果表明 :桂淮 2号叶芽蛋白质含量2 .82 % ,低于豌豆苗而高于其他多种芽苗菜 ;膳食纤维在同类蔬菜中含量最高 ,达 4 .4 6 % ;经小鼠MTD毒性试验属无毒级 ;作蔬菜食用 ,色、香、味俱佳 ,口感爽脆嫩滑 ,风味独特