Inheritance of slow rusting to stem rust in wheat

Summary The inheritance of the slow rusting character was studied on F₅ progenies from seven spring wheat cultivars (Triticum aestivum) crossed in all possible combinations without reciprocals. The cultivars and their progenies were evaluated for slow rusting in 1974 and 1975 in epidemics of Puccinia graminis f. sp. tritici, races 15 and 151, and traces of other races. Slow rusting varied significantly among the parents and among the F₅ progeny of each cross. Transgressive segregation occurred in each cross, i.e. some progeny rusted more slowly than the parents and some faster. In crosses with both Idaed 59 and Kenya 58 the progeny distributions were skewed towards slow rust development but the distributions in the other crosses were normal. The genetic control of slow rusting was predominantly additive, and narrow sense heritability was approximately 80 percent. The number of segregating genes having an effect on slow rusting was estimated to be 2 to 12 pairs depending on the cross. Correlation between slow rusting and maturity was usually negative but in most crosses the relationship was small.Contribution No. 9624 from the Agricultural Experiment Station, University of Minnesota, St. Paul, Minnesota 55108.     

浅圆仓储粮应用磷化氢熏蒸的建议

本文对浅圆仓储粮中需要进行磷化氢熏蒸时的几种情况进行了讨论，包括粮堆基本均温时的熏蒸处理、冬后负温差粮的熏蒸、空间与表层的熏蒸、局部或深层部位的害虫熏蒸等，并对这几种情况下可采用的措施和应注意的问题提出了建议。     

立筒仓局部环流熏蒸杀虫试验

利用粮堆局部处理机对立筒仓进行局部环流熏蒸试验，可有针对性地杀死局部害虫，节省用药量，降低能耗，减少储粮损失，提高经济效益。     

高大平房仓内环流熏蒸新技术初探

对高大平房仓膜下内环流熏蒸进行试验。由于内环流管网风道布置合理，熏蒸气体在高大粮堆中均匀分布，各部位PH3浓度快速达到有效浓度，解决了高大平房仓的熏蒸难题。文章对该技术的优点及有待解决的问题进行了讨论。     

Application of Triticum monococcum for the improvement of triticale resistance to leaf rust (Puccinia triticina)

The aim of this work was to evaluate the leaf rust resistance introduced into introgressive triticale lines with Triticum monococcum genes, and to study the expression of these genes at the hexaploid level. The introgressive lines were developed by incorporating diploid wheat (T. monococcum s.s.) genes into hexaploid triticale LT 522/6 using the synthetic allotetraploid T. monococcum/Secale cereale (A^mA^mRR) as a bridging form. A group of 44 those lines, parental stocks and check cultivars were inoculated at the seedling stage (in a greenhouse) and at the adult‐plant stage (in the field) with four pathotypes of Puccinia triticina. At the seedling stage the assessment of infection type showed that four lines had resistance to all pathotypes as high as in the T. monococcum donor. Adult plant examinations showed some introgressive lines with complete resistance and also lines with partial resistance, expressed in area under the disease progress curve (AUDPC) calculations as slow rusting. Some lines comprise low AUDPC with complete resistance at seedling stage.     

西南地区浅圆仓储粮特性研究

通过对西南地区浅圆仓的隔热性能、气密性能、相配套的环流熏蒸系统以及通风系统性能的研究，总结出一些经济而有效的储粮方法，以指导储粮工作。     

新建平房仓磷化氢环流熏蒸杀虫试验

文章主要论述磷化氢环流熏蒸中，仓房气密性与熏蒸浓度的关系、“动态潮解”产气法的简便性和经济性，并提出了在目前仓房条件下应采用的熏蒸浓度与密闭时间。     

施用不同缓释肥料对春小麦产量的影响

通过对Triabon和Field两种缓释肥料的试验研究,结果表明:缓释肥料具有良好的养分缓释效果,肥效期均可达到100d,但Triabon缓释效果优于国产的Field。施用缓释肥料Triabon600kg/hm2,春小麦单产7083kg/hm2,比对照增产42 5%,且穗粒数、千粒重均较对照增加明显,Field次之。施用缓释肥料的籽实、茎叶N、P、K携出量分别比等NPK养分混配肥料S提高了2 4%～14 8%,5 6%～21 2%,8 0%～11 3%。缓释肥料的N利用率达到37 2%～60 9%,P利用率24 7%～40 3%,K利用率71 3%～81 9%,减少了肥料损失。     

Impact of soil fumigation practices on soil nematodes and microbial biomass

This study was designed to understand the impact of methyl bromide (MB) (CHaBr) and its alternatives on both free-living and root-knot nematodes in the soil. A randomized complete block experiment with six treatments and 4 replicates (each replicate in a separate greenhouse) was established in Qingzhou, Shandong Province, China. In addition to MB and untreated control (CK) treatments there were four alternative soil fumigation practices including MB virtually impermeable films (VIF), metam sodium (MS), MS VIF and soil solarization combined with selected biological control agents (SS BCA). Two tomato (Lycopersicum esculentum Mill.) cultivars, cv. Maofen-802 from the Xian Institute of Vegetable Science, China, and cv. AF179 Brillante from the Israeli Hazera Quality Seeds, were selected as test crops. The results indicated that Rhabditidae was the most dominant population with percentage abundance as high as 85% of the total number of identified free-living nematodes, followed by that of Cephalobidae. Methyl bromide and its alternatives except for the non-chemical SS BCA treatment controlled the target pest, root-knot nematodes. Also, the impact of the three chemical alternatives on free-living nematode number and functional group abundance was similar to the impact associated with a typical methyl bromide application. Chemical fumigation practices, especially that with MB, significantly reduced the number of nematodes in the soil and simultaneously significantly reduced the number of nematode genera thereby reducing nematode diversity. All the four soil chemical fumigation activities decreased soil microbial biomass and had an obvious initial impact on microorganism biomass. Furthermore, both plant-parasitic and fungivore nematodes were positively correlated with soil microbial biomass.