浅圆仓径向通风技术研究

为提高浅圆仓储粮通风均匀性,解决因入库自动分级产生的通风死角问题,同时提高通风效率,降低吨粮保管费用,基于计算机数学仿真模拟技术,研发了浅圆仓径向通风系统。通过实仓试验发现,该系统基本解决了浅圆仓中心单点入库后的通风均匀性,以及通风过程中水分分层较大的问题,有效提高了储粮稳定性。     

多功能减压管在立筒仓和浅圆仓中的应用

在立筒仓及浅圆仓中安装多功能通风熏蒸减压降碎装置,可以有效降低粮食入库破碎率,减少自动分级影响,减缓出库时粮堆整体移动产生的动载荷,保护仓内设施,延长筒仓及浅圆仓使用寿命.同时利用多功能减压管进行内环流熏蒸及通风降温降湿进一步完善了立筒仓及浅圆仓储粮性能,提高了储粮稳定性.     

浅圆仓多点均衡落料布料器对粮堆均匀性的影响

浅圆仓入仓时产生自动分级,影响通风、熏蒸等粮情处理效果。试验表明:通过多点均衡落料,降低了自动分级程度,通风均匀性好,达到了安全储粮的目的。     

秋冬季环流均温通风在浅圆仓储粮中的应用

为有效解决浅圆仓机械通风过程中存在的通风死角严重、通风时间长、水分损失严重、通风均匀性差、通风能耗高等问题,我库对通风工艺进行了改进。常规机械通风将平均粮温降至目标范围内后,再利用两台离心风机配合单管风机对浅圆仓进行内环流均温通风,充分利用四周粮堆冷源,均衡中心部位的高温粮。较好地解决了浅圆仓常规机械通风中存在的问题。     

谷物冷却机在浅圆仓储粮中的应用研究

通过对浅圆仓内储藏的小麦进行谷物冷却机冷却通风处理，实时检测入仓冷空气的温湿度、粮食温度及含水量的变化，探索谷冷机在浅圆仓中应用的可行性和经济性。结果表明通过谷物冷却通风可迅速有效地降低储粮的温度，并减少粮堆内的温差和水分梯度，提高了储粮的安全性和稳定性。     

浅圆仓氮气气调尾气利用技术研究

通过对浅圆仓气调储粮排放的尾气回收利用,缩短浅圆仓群落总体气调充气时间,降低了浅圆仓氮气气调储粮吨粮成本,应用效果良好,实现了气调防治虫霉的目的。     

中温高湿储粮区的进口大豆浅圆仓绿色集成工艺储藏实践

针对进口大豆储藏特性差的特点，以中温高湿储粮区的进口大豆浅圆仓存储为例，集成机械通风技术、富氮气调技术、内环流均温技术和空调控温技术等绿色储粮措施，结合储粮区气候特点，选择适当的储粮技术应用时机，开展了进口大豆浅圆仓绿色集成工艺储藏实践。结果表明：该绿色集成储藏工艺可实现中温高湿储粮区浅圆仓进口大豆长期安全储藏，可降低0.595 kW·h/t的吨粮保管能耗。以期为中温高湿储粮区的进口大豆浅圆仓绿色储藏技术应用提供参考。     

浅圆仓充氮期间仓墙四周排积热试验

为了延缓储粮充氮度夏期间浅圆仓仓墙四周所储玉米品质的劣变,特别是脂肪酸和水分的变化。通过改造环流通风系统,综合利用智能充氮系统、空调控温以及仓壁排积热环流通风系统排除仓墙四周积热,促进粮堆上层空气流动。达到了预期效果,实现了安全储粮。同时,此方法还减少了人工翻动和谷冷机费用,经济效益显著。     

浅圆仓多点均衡落料布料器对大豆杂质分布的影响

浅圆仓进粮过程中,会发生较严重的自动分级现象,大豆杂质聚集于落料点下方,杂质集聚区因带菌量大、破碎率高,极易发热,这些部位又因孔隙度低,无法得到有效通风,是大豆保管工作中的难点。研究了通过多点均衡落料布料器分散杂质落料点,以改善其杂质分布不均的情况。     

浅圆仓中心高杂区气流途径与热量转移规律的探讨

机械通风是处理粮堆发热和冬季降低粮堆温度的一种有效的手段.目前,根据通风的目的和仓型的不同,各种不同风压、风量的风机和通风方式应运而生.随着节能减排和科学保粮要求,对通风效率的要求越来越高.同时,在粮堆的物理性质中,粮堆的孔隙度、吸湿性及自动分级与出粮机械通风有着密切的关系,它直接影响着机械通风储粮有关参数的选择与通风效果.这也要求我们不断的试验、探索,总结相关经验,本文根据浅圆仓的具体情况,在试验的基础上总结分析了风压与通风气流途径的关系,为提高浅圆仓通风效率和效果,避免有害通风提供了试验数据和借鉴.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Mechanisms and diversity of resistance to sorghum shoot fly,Atherigona soccata

Sorghum shoot fly, Atherigona soccata, is one of the important pests of postrainy season sorghums. Of the 90 sorghum genotypes evaluated for resistance to this pest, RHRB 12, ICSV 713, 25026, 93046 and 25027, IS 33844‐5, Giddi Maldandi and RVRT 3 exhibited resistance in postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, 5622, 17726, 18368 and 34722, RVRT 1, ICSR 93031 and Dagidi Solapur showed resistance in rainy season, suggesting season‐specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35‐1, ICSV 700, 711, 25010, 25019 and 93089, IS 18662, Phule Vasudha, IS 18551 and 33844‐5 and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the resistance mechanism. Five genotypes exhibited resistance with high grain yield across seasons. Correlation, path and stepwise regression analyses indicated that leaf glossiness, seedling vigour, trichome density, oviposition and leaf sheath pigmentation were associated with the expression of resistance/susceptibility to shoot fly, and these can be used as marker traits to select and develop shoot fly‐resistant sorghums.     

Reaction of tritordeum to Fusarium culmorum and Septoria nodorum

Summary Hordeum chilense is a wild barley extensively used in wide crosses in the Triticeae. It could be a valuable source of resistance to Fusarium culmorum and Septoria nodorum. Some H. chilense x Triticum spp. amphiploids, named tritordeums, were more resistant than the parental wheat line to these diseases, others were not. Average contents of ergosterol and deoxynivalenol (DON) suggested that resistance to colonization by Fusarium was the highest for Hordeum chilense, followed by tritordeum and wheat in decreasing order. In particular, the H. chilense genotypes H7 and H17 enhanced the wheat resistance to F. culmorum in its tritordeum offsprings. Resistance to S. nodorum in tritordeum was not associated with tall plant height. There is sufficient genetic variation for resistance to F. culmorum and S. nodorum among tritordeum to allow the breeding of lines combining short straw and resistance to both diseases.     

Disease resistance in protected crops and mushrooms

Summary Cultivars of tomatoes, cucumbers, lettuce and peppers have been bred for resistance to one or more pathogens. Some tomato and cucumber cultivars have resistance to a wide range of diseases. Resistance has been transient in many cases and a succession of cultivars with new genes or new combinations of resistance genes has been necessary to maintain control. There has been a number of notable exceptions and these have included durable resistance to such pathogens asFulvia fulva and tomato mosaic virus. With lettuce the resistance situation is complicated by the occurrence of fungicide resistant pathotypes. There are no strains ofAgaricus bisporus purposely bred for disease resistance.In protected flower crops only resistance to Fusarium wilt in carnations has been purposely bred but differences in disease resistance are apparent in cultivars of many ornamental crops. This is particularly so in chrysanthemums where there are cultivars with resistance to many of the major pathogens. Similar situations occur with other flower crops and pot plants. Cultivars of some species have not been systematically investigated for resistance.The need for genetic resistance will increase with the further reduction, in the limits on pesticide use and an increasing public awareness and importance of pesticide pollution.ADAS is an executive agency of the Ministry of Agiculture, Fisheries and Food and the Welsh Office.     

Genetic constitution and diversity in four narrow endemic redwoods from the family Cupressaceae

The genetic constitution and diversity of four relictual redwoods are discussed in this review. These include monotypic genera of the family Cupressaceae: coast redwood (Sequoia sempervirens), giant sequoia (Sequoiadendron giganteum), dawn redwood (Metasequoia glyptostroboides), and alerce (Fitzroya cupressoides). All four species are narrow endemics, share a number of common phenotypic traits, including red wood, and are threatened species. Fossil history suggests that the ancestors of redwoods probably originated during the Cretaceous and Tertiary periods and flourished thereafter for millions of years. Towards the end of the Tertiary period began their decline and struggle for existence that continued during the subsequent geologic upheavals and climate changes, until the survival of the present-day redwoods in the current restricted locations in the world (USA, China, and South America). Although two species, Sequoiadendron and Metasequoia, are diploids (2n = 22), and the other two are polyploids: Fitzroya a tetraploid (2n = 4x = 44), and Sequoia a hexaploid (2n = 6x = 66); they all share the same basic chromosome number x = 11. The genome size in the hexaploid Sequoia is one of the largest (31,500 MB) in the conifers, while the genome sizes of diploid Metasequoia and Sequoiadendron are about one-third (~10,000 MB) of Sequoia. Genetic diversity in the redwoods is lower than most other gymnosperms, except in Sequoia, which seems to rank near the upper quarter of the coniferous forest trees. Genomic research is sparse in the redwoods, and should be pursued for a better understanding of their genome structure, function, and adaptive genetic diversity.     

The induction in vitro of adventitious shoots in Rosa

Summary Adventitious shoots were formed on excised leaves, roots and callus of Rosa persica x xanthina and on excised leaves of R. laevigata and R. wichuraiana on culture media that included BAP and NAA as growth regulators. Shoots formed freely on freshly cultured callus of R. persica x xanthina but their production declined in successive cultures and ceased after twelve weeks. Transplantation to soil was improved by rooting plantlets in cellulose plugs in vitro and transferring plantlets to soil while still in the plugs.     

Distribution,ecology and reproductive biology of wild tomatoes and related nightshades from the Atacama Desert region of northern Chile

Over the past 20 years, several expeditions were made to northern Chile to collect populations of wild tomatoes (Solanum chilense, S. peruvianum) and allied nightshades (S. lycopersicoides, S. sitiens), and obtain information about their geographic distribution, ecology and reproductive biology. Restricted mainly to drainages of the Andean and the coastal cordillera, populations are geographically fragmented. The two nightshade species are rare and threatened by human activities. Adaptation to extreme aridity and soil salinity are evident in S. chilense and S. sitiens (the latter exhibits several xerophytic traits not seen in the tomatoes) and to low temperatures in S. lycopersicoides and S. chilense. All tested accessions are self-incompatible, with the exception of one S. peruvianum population collected at the southern limit of its distribution. Several distinguishing reproductive traits—anther color, attachment, and dehiscence, pollen size, and flower scent—suggest S. sitiens and S. lycopersicoides attract different pollinators than S. chilense and S. peruvianum. The four Solanum spp. native or endemic to Chile provide a variety of novel traits which, through hybridization and introgression with cultivated tomato, could facilitate development of improved varieties, as well as research on a variety of basic topics, including plant-pollinator interactions, abiotic stress responses, and evolution of reproductive barriers.     

The exploration of genetic resources of Portuguese cabbage and kale for resistance to several Brassica diseases

Summary Twenty three accessions of nine Portuguese cabbage and kale land races from different geographic origins were tested at the seedling stage for resistance to several important brassica diseases. Resistance to downy mildew (Peronospora parasitica), expressed as necrosis of the cotyledon mesophyll, was found in all the accessions. Type A resistance to cabbage yellows (Fusarium oxysporum f. sp. conglutinans race 1) was present in most of the landraces. Resistance to clubroot (Plasmodiophora brassicae race 6) was found in one accession of the Portuguese tree kale. High resistance to blackleg (Leptosphaeria maculans) and white rust (Albuco candida) was not detected, although several accessions showed 20 to 30% of plants with intermediate expression of resistance. All Portuguese cole accessions were susceptible to blackrot (Xanthomonas campestris pv. campestris).     

Production and characterization of intergeneric diploid cybrids derived from symmetric fusion between Microcitrus papuana Swingle and sour orange (Citrus aurantium)

Plants were regenerated from intergeneric somatic hybridization between embryogenic protoplasts of Microcitrus papuana Swingle and leaf-derived protoplasts of sour orange (Citrus aurantium L.) via electrofusion. The regenerated plants were morphologically similar to the leaf parent in growth vigor, leaf and branch structure. FCM analysis showed that they were diploids. Simple-sequence-repeat (SSR) and cleaved-amplified-polymorphic-sequence(CAPS) were employed for hybridity characterization. SSR banding patterns of the regenerated plants were identical to the leaf parent, sour orange, indicating that they possessed nuclear component derived from sour orange. DNA amplification with chloroplast and mitochondrial universal primers, followed by restriction endonuclease digestion, revealed polymorphism between the fusion parents. Therefore, this method was used to determine the cytoplasmic compositions of the regenerated plants. Banding patterns for all the polymorphic primer/enzyme combinations of the regenerated plants were similar to those of the embryogenic parent, M. papuana, suggesting that only the cytoplasmic components derived from the embryogenic parent were present in the regenerated plants. FCM, SSR and CAPS demonstrated that intergeneric diploid cybrids have been successfully obtained by symmetric fusion. Related results concerning nuclear and cytoplasmic composition of previous diploid somatic hybrids and potential mechanism for regeneration of such kind of plants are discussed herein. This revised version was published online in July 2006 with corrections to the Cover Date.     

Breeding barriers between the cultivated strawberry, Fragaria × ananassa, and related wild germplasm

Five-hundred interspecific and intergeneric crosses were performed among accessions of the wild strawberries Fragaria vesca(2x), Duchesnea indica (8x), Potentilla tucumanensis (2x) and 9 genotypes of the cultivated strawberry, Fragaria×ananassa (8x), following an incomplete diallele mating design. Crosses between D. indica and F.×ananassa produced many putative hybrids when D. indica was used as female but a few achenes and plants when used as male; therefore, pollen-pistil compatibility relations were analyzed by fluorescence microscopy in this direction of the cross. Of the genotypic combinations, 78.6% were incompatible at the stigma level and 17.2% at the first third of the style. Only 3.6% were pollen-pistil compatible and produced fruits with achenes (seven did not germinate or originated short-lived plants and nine produced normal plants). F.vesca×F.×ananassa crosses produced 35 hybrid achenes but only 14% germinated, yielding short-lived plants; histological analyses revealed that inviable seeds had less developed (or collapsed) endosperms and smaller embryos than control plump F. vesca seeds. P.tucumanensis was only used as male, with negative results. These species and genera are partially isolated by a complex system of pre- and post-zygotic barriers. Knowledge of their nature would allow the breeder to devise strategies to put the genetic variability available in the group into a useful form. This revised version was published online in July 2006 with corrections to the Cover Date.