Allelism of two genes for stem rust resistance in triticale

Summary Inheritance studies involving Coorong and Satu triticales showed that each possessed a single dominant gene for resistance. The genes were allelic or closely linked. The relative frequencies of Sr27 (Coorong gene) and Sr _Satuin a sequence of International Triticale Screening Nurseries were similar. However, a significant increase in the frequency of entries with Sr_Satu occurred in the 17 International Triticale Screening Nursery (ITSN).     

Restoration of giant cardon cacti in barren desert soil amended with common compost and inoculated with Azospirillum brasilense

Barren desert soil that otherwise could not support perennial plant growth was amended with six levels of common agricultural compost. Seedlings of the giant cardon cactus, one of the primary plant species responsible for soil stabilization in the southern Sonoran Desert, were inoculated with the plant-growth-promoting bacterium Azospirillum brasilense Cd, planted, and grown for 18 months under nursery conditions typical for slow-growth cacti. Control plants were grown without compost amendment, without inoculation (negative control), or in fertile, rare “resource island” soil preferred by cardon seedlings (positive control). During the prolonged growth period, the decisive factor in seedling growth in barren soil was the addition of small amounts of common compost; 6 to 25% of the growth substrate volume gave the best growth response and, to a lesser extent, so did inoculation with A. brasilense Cd. Although the bacteria significantly affects plant growth when amended with “resource island” soil and added to barren soil, its effect on plant growth was far smaller than when compost alone was added. Compost added to barren soil significantly increased the dry weight parameters of the plant to almost similar levels obtained by the “resource island” soil; however, the compost amendment supports a more voluminous and greener plant with elevated pigment levels. This study shows that barren soil supplemented with compost can replace the rare “resource island” soil for cardon nurseries destined to abate soil erosion in the desert.     

空气整根育秧盘播种装置的试验研究

介绍了一种适于工厂化育苗的新型播种装置的结构及工作原理，通过试验对其中的几个基本参数进行了研究，分析得出了最优生产条件，经试验验证，该机具有单粒率高及空穴率、重播率低等优点。     

Dietary inclusion of multispecies probiotics to reduce the severity of post-weaning diarrhea caused by Escherichia coli F18+ in pigs

This study was aimed to determine the efficacy of multispecies probiotics in reducing the severity of post-weaning diarrhea caused by enterotoxigenic Escherichia coli (ETEC) F18⁺ on newly weaned pigs. Thirty-two pigs (16 barrows and 16 gilts, BW = 6.99 ± 0.33 kg) at 21 d of age were individually allotted in a randomized complete block design with 2 × 2 factorial arrangement of treatments. Pigs were selected from sows not infected previously and not vaccinated against ETEC. Pigs were fed experimental diets for 25 d based on 10 d phase 1 and 15 d phase 2. The factors were ETEC challenge (oral inoculation of saline solution or E. coli F18⁺ at 2 × 10⁹ CFU) and probiotics (none or multispecies probiotics 0.15% and 0.10% for phase 1 and 2, respectively). Body weight and feed intake were measured on d 5, 9, 13, 19, and 25. Fecal scores were measured daily. Blood samples were taken on d 19 and 24. On d 25, all pigs were euthanized to obtain samples of digesta, intestinal tissues, and spleen. The tumor necrosis factor alpha (TNFα), malondialdehyde (MDA), peptide YY (PYY), and neuropeptide Y (NPY) were measured in serum and intestinal tissue. Data were analyzed using the MIXED procedure of SAS. The fecal score of pigs was increased (P < 0.05) by ETEC challenge at the post–challenge period. The ETEC challenge decreased (P < 0.05) jejunal villus height and crypt depth, tended to increase (P = 0.056) jejunal TNFα, increased (P < 0.05) ileal crypt depth, and decreased (P < 0.05) serum NPY. The probiotics decreased (P < 0.05) serum TNFα, tended to reduce (P = 0.064) jejunal MDA, tended to increase (P = 0.092) serum PYY, and increased (P < 0.05) jejunal villus height, and especially villus height-to-crypt depth ratio in challenged pigs. Growth performance of pigs were not affected by ETEC challenge, whereas the probiotics increased (P < 0.05) ADG and ADFI and tended to increase (P = 0.069) G:F ratio. In conclusion, ETEC F18⁺ challenge caused diarrhea, intestinal inflammation and morphological damages without affecting the growth performance. The multispecies probiotics enhanced growth performance by reducing intestinal inflammation, oxidative stress, morphological damages.     

成都郊区苗木及草坪经济发展趋势与对策探讨

以成都郊区温江为例,利用大量的调查数据分析了该地区苗木及草坪发展的现状及面临的问题,并有针对性的提出了几点对策。     

贵州特有种子植物种质资源与利用评价研究

贵州植物区系起源古老，特有和孑遗种类较多。贵州特有种子植物约有280余种，分属66科、144属，占全种子植物科属种的比值分别为33．8％、10．3％和5．3％，而且分布31个中国特有单型属和黔苣苔属（Tegia）、辐花苣苔属（Thamnocharis)、假胡麻属（Centrantheropsis)和歧柱蟹甲草属（Dicercodados) 4个贵州特有属。这些贵州特有植物是贵州森林资源组成的不同替代成分，并都具有多种生物学和重大经济价值。本文从重要用材林和园林观赏树种中遴选出如梵净山冷杉（Abies fanjingshanensis) 等60余种，对其自然分布地域及生境、经济价值及利用评价、资源现状、种质资源的保护与利用、狭限分布机理等进行了广泛的调查和统计分析；选择20种代表植物开展引种栽培与种苗扩繁试验取得了成功，其原产地与引入地海拔高度相近地区（1000m左右）的物种植株迁地栽培成活率和采种播种出苗纺的概率加权平均值均较高（75％－95％），并且这两和数学期望值的坐标 曲线极为相似；供试植物的扩繁系数为0．61－1。还提出了贵州特有植物种质资源的可持续利用途径及模式探讨。     

复合有机基质对黄瓜幼苗生长的影响

采用蛭石、草炭、珍珠岩、有机肥、腐熟鸡粪、炉渣灰等原料组成复合基质，进行黄瓜穴盘育苗。通过对基质的理化特性分析，以M2（70%蛭石 20%有机肥 105炉渣灰）和M3（70%蛭石 20%鸡粪 10%炉渣灰）的容重、比重、总孔隙度以及pH值、有机质含量、EC、TDS等指标符合育苗基质的要求，不同基质处理对黄瓜幼苗的影响存在显著差异。其中处理M2和处理M3的黄瓜幼苗生长势、矿质元素吸收以及秧苗质量等均明显优于其它处理。     

甘露寡糖对保育猪的营养与保健作用

大量研究表明,甘露寡糖(MOS)通过积极影响断奶仔猪的肠道微生物菌群和肠道形态结构,加速由于断奶饥饿应激或采食固体饲料中抗原受损伤的肠黏膜上皮的修复,有助于保持仔猪断奶后肠道的完整性和消化吸收功能。在免疫反应方面,MOS通过促进抗原提呈增强断奶仔猪的抗病性,从而增强从先天性免疫应答向适应性免疫应答的转变。     

“十一五”我国设施蔬菜生产和科技进展及其展望

近年来,我国设施蔬菜生产发展极其迅速,生产面积以每年10 %以上的速度在增长,形成了不同区域特色的设施类型、生产模式和技术体系。本文分析了近五年我国设施蔬菜产业发展特点,并从设施装备研发、设施蔬菜生物学与基因功能研究、设施蔬菜育苗技术、资源高效利用与连作障碍克服技术、抗逆与调控技术、优质与安全生产技术等方面总结了我国近年来取得的主要科技成就。最后在分析我国当今设施蔬菜生产中存在的主要问题的基础上,探讨了我国今后设施蔬菜产业和科研的发展方向。     

北京温室大棚有机黄瓜育苗及施肥效果研究

以黄瓜为对象,通过在黄瓜育苗时添加不同土壤添加物质和在根瓜采收后追施不同的肥料来筛选出比较理想的土壤添加物质和肥料,从而制定出一套适合北京温室大棚有机黄瓜生产的育苗和施肥技术。结果表明,用粗竹醋液200倍液和矿物肥40:1作为育苗时的土壤添加物质对苗高和茎粗有明显的促进作用;在根瓜采收后追施矿物肥1500kg/hm2、粗竹醋液510kg/hm2两个处理,可显著提高黄瓜总产量,其增产率分别为35.70%和30.76%。