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1.
粮堆高度对机械通风粮层阻力的影响 总被引：2，自引：0，他引：2
粮层阻力是设计储粮机械通风系统的一项重要参数。本文主要分析了粮堆高度对粮层阻力的影响,通过试验进行实测,并采用多元回归的方法,得出了新的经验公式P＝ahbvc。 相似文献
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机械通风粮层阻力测定 总被引：3，自引：0，他引：3
粮层阻力是粮粒对通过粮堆的气流形成的阻力,即在压力上表现为气流的静压降。它是粮堆通风、粮食干燥系统和计算机模拟过程中的一个重要参数。本试验对小麦、稻谷、玉米等七个品种粮食的粮层阻力值进行测定。用回归分析的方法,在计算机上对数据进行处理,得出了粮堆通风系统设计中粮层阻力的计算公式——P=ahv~6,其结果与实测值较为吻合,可以用于实际生产。 相似文献
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为了研究平房仓横向通风技术在玉米储藏上的应用效果,明确玉米储藏过程横向通风工艺及其参数,利用高大平房仓中设计安装的横向通风设施,以及在储藏玉米粮堆中预埋的插入式毕托管,对高大平房仓横向通风系统进行实仓测试。全面开展了玉米储藏过程中横向通风工艺应用研究,测试了在横向通风系统通风时,风速、风量、系统各部分阻力和粮堆压力分布。研究发现,在储藏玉米的高大平房仓中应用横向通风系统时,粮堆单位粮层阻力较小,在实用单位通风量时,横向通风系统总阻力不大于1200Pa;同时横向通风还具有风量分配均匀、粮堆通风均匀性良好的特点。该研究为玉米在配备横向通风系统的高大平房仓储藏提供了技术支持。 相似文献
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在储藏小麦的高大平房仓中,根据计算机测温系统测出的一年中粮温、仓温以及同时间温度计检测的仓外气温为基本参考数据,分析了气温、仓温、全仓平均粮温、各层平均粮温、四个方向平均粮温和各区域平均粮温的年变化规律。分析结果表明：正常情况下,气温影响仓温,仓温影响粮温。年变振幅：气温>仓温,仓温>粮温;仓温滞后气温,粮温滞后仓温。上层平均粮温受气温影响最大,中下层最小;各层平均粮温受气温影响大小为上层>中上层>下层>中下层。四周平均粮温随季节变化明显。东侧平均粮温一年中波动幅度最小。外围平均粮温受外界条件如日照、气温等影响很大,其次为中央区域,中环区域波动最小。区域测温点温度在方向分布上有很大差异,分析时所用数据为区域平均值,因此粮温曲线不能正确的完全反映区域变化。所以有待进一步对区域的划分进行科学的改进。 相似文献
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针对当前农户储粮钢板仓存在的问题,重点研究了造成钢板仓漏气的部位——各层接缝处、出粮口的气密防潮方式和结构,提出了加装层沿密封条、层间加装紧固扣件、仓圈边缘加工成螺纹状、密封出粮口设计、加装整体密封罩等多个经济、方便、实用的气密防潮性改造设计方案.并通过气密防潮仓与对照实验表明,增加层沿密封条和采用密封出粮口后,气密防潮仓内粮食的含水量变化明显较对照仓缓慢,仓房防潮性能明显提高.在人为改变环境温度后,对照仓内的上层粮温明显高于气密防潮仓内的粮温,气密防潮仓的隔热性能也得到了提高. 相似文献
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立筒库储粮面层磷化铝熏蒸杀虫的初步探讨 总被引：1，自引：0，他引：1
本文对立筒库储粮害虫的发生，发展和分布情况，以及进行粮面Ａ１Ｐ熏蒸的密闭技术，ＰＨ３的渗透，残留情况和杀虫效果作了初步探讨。结果表明：原始无虫粮在筒库内存放６０天后，开始面层感染害虫，并逐渐向深层发展。但害虫休中在粮面３ｍ以内，１２０天后面层虫口密度可达１００头／ｋｇ以上；粮层中１０ｍ处害虫亦能生存和繁殖，以粮层８ｍ计，８ｇ／ｍ＾３的Ａ１Ｐ剂量熏蒸，能彻底杀死６ｍ以内常见的储粮害虫；熏蒸密闭时要要 相似文献
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针对春夏季粮温上升,导致粮食品质下降、虫霉危害增加的问题,利用杭嘉湖地区丰富的地下水资源和高效换热器技术,研发地下水风机盘管机组控制仓温工艺技术。实仓试验结果表明,该技术能够有效地控制仓内空间空气温度,最高仓温低于26℃,粮堆上层最高粮温低于25℃,同时延缓各层粮温的上升,并将整仓平均粮温控制在18.3℃以内。对照仓最高仓温约为36℃,粮堆上层最高粮温从第四周开始高于25℃,最高达到28.7℃,同时各层粮温的上升速度较快,整仓平均粮温达到21.0℃。使用该技术11周,吨粮电耗成本为1.175元。因此,应用该技术在试验仓实现了准低温储粮,在保证储粮安全方面发挥了重要的作用。 相似文献
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Alessandro Infantino Mohamed Kharrat Luca Riccioni Clarice J. Coyne Kevin E. McPhee Niklaus J. Grünwald 《Euphytica》2006,147(1-2):201-221
Summary Soil-borne fungal diseases are among the most important factors, limiting the yield of grain legumes in many countries worldwide.
Root rot, caused by Aphanomyces euteiches, Rhizoctonia solani, Fusarium solani and wilt, caused by several formae speciales of Fusarium oxysporum are the most destructive soil-borne diseases of pea, chickpea, lentil, fababean and lupin. The most effective control of
these diseases is achieved through the use of resistant varieties. In this paper, recent advances in conventional and innovative
screening methods for disease resistance are presented. Many grain legume accessions, which are maintained in national and
international germplasm collections, have been evaluated for disease resistance and numerous resistant varieties have been
released following incorporation of identified resistance genes from these sources. Recent identification of molecular markers
tightly linked to resistance genes has greatly enhanced breeding programs by making marker assisted selection (MAS) possible
and allowing the development of varieties with multiple disease resistance. Progress in the understanding of the biology of
soil-borne fungal pathogens of grain legumes is also reviewed with particular reference to the genetic structure of their
populations, diagnosis and host–pathogen interaction. 相似文献
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M. Farooq N. Gogoi S. Barthakur B. Baroowa N. Bharadwaj S. S. Alghamdi K. H. M. Siddique 《Journal of Agronomy and Crop Science》2017,203(2):81-102
Water scarcity is a major constraint limiting grain legume production particularly in the arid and semi‐arid tropics. Different climate models have predicted changes in rainfall distribution and frequent drought spells for the future. Although drought impedes the productivity of grain legumes at all growth stages, its occurrence during reproductive and grain development stages (terminal drought) is more critical and usually results in significant loss in grain yield. However, the extent of yield loss depends on the duration and intensity of the stress. A reduction in the rate of net photosynthesis, and poor grain set and grain development are the principal reasons for terminal drought‐induced loss in grain yield. Insight into the impact and resistance mechanism of terminal drought is required for effective crop improvement programmes aiming to improve resistance to terminal drought in grain legumes. In this article, the impact of terminal drought on leaf development and senescence, light harvesting and carbon fixation, and grain development and grain composition is discussed. The mechanisms of resistance, management options, and innovative breeding and functional genomics strategies to improve resistance to terminal drought in grain legumes are also discussed. 相似文献
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Eight concrete beams reinforced with 500MPa steel bars and four reinforced with 400MPa ultra fine grain steel bars were tested under two point symmetrical concentrated static loading to observe the details of crack pattern development on these beams and investigate their cracking characteristics. It was shown that the cracking behavior of the beams with high strength bars was essentially similar to that of common RC flexural members, whereas the computed crack widths using the formula adopted in the Code for Design of Concrete Structures GB 50010 2002 exceeded that of the experiment under the normal service. Furthermore, the formulas for crack spacing and crack width specified in GB 50010 2002 were evaluated through the experimental results and previous studies of sixty seven concrete beams reinforced with high strength bars. On the basis of the calculation model in GB 50010 2002, revised formulas for crack spacing and crack width were proposed. The values calculated by revised formulas were in good agreement with the test results. 相似文献
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Twenty-two sorghum genotypes were evaluated for grain mould response, 13 morphological and biochemical traits thought to contribute
to resistance, and 3 agronomic traits related to utilization. Measurements of grain mould (field grade score, threshed grade
score, ergosterol content, and percentage germination) were strongly correlated with one another. Highly significant correlations
between measures of grain mould and seed hardness, seed phenol content in acid methanol extract, and glume colour indicated
that they strongly affected grain mould response. Harder grain, higher levels of seed phenols, and darker glumes contributed
to grain mould resistance. Weaker and less consistent correlations between measures of grain mould and seed colour, seed flavan-4-ol
content, glume phenol and flavan-4-ol contents, and glume cover indicated relatively less effect of these traits on grain
mould response. Genotype means indicated that combinations of several traits are required to achieve resistance. Germplasm
lines, including coloured-seeded lines IS 14375, IS 14387, IS 18144, and IS 18528, and white-seeded lines IS 21443, IS 24495
and IS 25017, showed greatest grain mould resistance. Improved lines generally had poorer grain mould resistance than these
landraces. However, the best improved lines were comparable in resistance to white-seeded landraces. B58586, IS 14375 and
IS 14387 are hard-seeded guinea sorghum lines that can be used as sources of grain mould resistance for West Africa. SP 33316,
SP 33349 and GM 15018 are agronomically elite lines that can be used as sources of grain mould resistance for further improvement
of white-seeded sorghum for South Asia and other regions.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Marker assisted introgression of bacterial blight resistance in Samba Mahsuri,an elite indica rice variety 总被引：1，自引：1，他引：0
Raman M. Sundaram Manne R. Vishnupriya Sunil K. Biradar Gouri S. Laha Gajjala Ashok Reddy N. Shobha Rani Nukala P. Sarma Ramesh Venkata Sonti 《Euphytica》2008,160(3):411-422
Samba Mahsuri (BPT5204) is a medium slender grain indica rice variety that is very popular with farmers and consumers across
India because of its high yield and excellent cooking quality. However, the variety is susceptible to several diseases and
pests, including bacterial blight (BB). We have used PCR based molecular markers in a backcross-breeding program to introgress
three major BB resistance genes (Xa21, xa13 and xa5) into Samba Mahsuri from a donor line (SS1113) in which all the three genes are present in a homozygous condition. At each
backcross generation, markers closely linked to the three genes were used to select plants possessing these resistance genes
(foreground selection) and microsatellite markers polymorphic between donor and recurrent parent were used to select plants
that have maximum contribution from the recurrent parent genome (background selection). A selected BC4F1 plant was selfed to generate homozygous BC4F2 plants with different combinations of BB resistance genes. The three-gene pyramid and two-gene pyramid lines exhibited high
levels of resistance against the BB pathogen. Under conditions of BB infection, the three-gene pyramid lines exhibited a significant
yield advantage over Samba Mahsuri. Most importantly, these lines retain the excellent grain and cooking qualities of Samba
Mahsuri without compromising the yield as determined in multi-location trials. This work demonstrates the successful application
of marker-assisted selection for targeted introgression of multiple resistance genes into a premium quality rice variety.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
R. M. Sundaram and M. R. Vishnupriya have contributed equally to this work. 相似文献
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为提高我国大面积应用的两系光温敏不育系培矮64S的稻瘟抗性,本研究通过杂交转育与分子标记选择相结合的途径,利用RM3330与RM262为标记,将Pi25与Pi-d(t)基因成功聚合于培矮64S中,经抗性、不育性、综合农艺性状评价,获得了5个基因型纯合且农艺性状稳定的F8代抗性改良候选不育系。抗性鉴定结果显示,抗性改良候选不育系及其抗性组合的叶瘟病情指数平均降幅为18.78%和23.24%,穗颈瘟病情指数平均降幅为18.58%和58.45%,抗性提高幅度极显著。育性观测结果表明抗性改良候选不育系不育度都在99.5%以上,柱头外露降低5.64%,包颈粒率降低8.55%。经济性状调查结果显示不育系除穗粒数下降、有效穗增加外,其余经济性状变化不明显;试配的杂交组合平均理论产量和实际产量比对照提高16.22%和6.89%,增产极显著。这些结果表明,通过Pi25与Pi-d(t)基因的导入显著提高了培矮64S稻瘟病抗性,获得了实用的光温敏不育系新材料。 相似文献
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储粮害虫PH3抗性机理及分子监测研究进展 总被引：1，自引：1，他引：0
储粮害虫PH3抗性一直倍受关注。在过去几十年中,人们对储粮害虫PH3抗性产生的生化机理进行了广泛的研究,但尚无定论。近年来,随着分子生物学的发展,储粮害虫PH3抗性分子监测方面的研究也日益受到重视。综述了储粮害虫PH3抗性产生的生化机制及PH3抗性分子监测方面的研究进展。 相似文献
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水分亏缺条件下冬小麦几个抗旱性状的应用价值 总被引：2，自引：2，他引：2
在盆栽水分亏缺条件下,以15个抗旱性不同的冬小麦品种(系)为材料,对其8个抗旱性状的应用价值进行了研究.结果表明,通过乳熟期旗叶气孔阻力和蒸腾速率、两种用水效率(分别用干重和粒重表示)对单株粒重进行选择,其效率比通过3个农艺性状(单株干重、株高、顶部3叶总面积)的要低得多,说明前者在抗旱育种中的应用价值不大. 相似文献