论棉花轻简化栽培

论述了棉花轻简化栽培的主要技术内容,对其发展作了展望。棉花轻简化栽培是指简化管理工序、减少作业次数,良种良法配套、农机农艺融合,实现棉花生产轻便简捷、节本增效、可持续发展的栽培管理措施和方法,是我国棉花科技工作者立足中国国情,通过对传统植棉技术创新改造而创建的新型栽培技术体系,是我国棉花生产由传统劳动密集型向轻简节本快乐型转变的重要支撑技术。棉花轻简化栽培技术体系主要包括单粒精播壮苗技术、简化整枝或免整枝技术、一次性施肥技术或水肥协同管理技术以及优化成铃集中收获等关键技术。展望未来,应在深入研究轻简化植棉生理生态学机理的基础上,进一步优化种植模式,创新完善关键栽培技术,研制新型物质装备,促进农艺技术和物质装备高度融合,为轻简化植棉提供更加有力的理论和技术支撑,推动棉花生产健康可持续发展。     

石河子垦区棉花膜下滴灌高密度高产栽培几项关键措施

随着棉花自动化灌溉技术的大力推广，棉花成本加大；提高棉花单产，降低生产成本，增加效益是增加团场职工收入。达到节水增产扩大社会效益的有效途径。农八师一二一团在总结8年来棉花滴灌实践的基础上，配合以高密度植棉技术使单产水平逐年提高。2003年在7～8月份极度干旱的条件下，     

棉花轻简化栽培关键技术及其生理生态学机制

棉花轻简化栽培是指采用现代农业装备代替人工作业、减轻劳动强度,简化种植管理、减少田间作业次数,农机农艺融合,实现棉花生产轻便简捷、节本增效的耕作栽培方式和方法。本文对轻简化栽培内涵、关键技术内容和相关生理生态学机制进行了总结性评述。实现棉花生产的轻便简捷、节本增效,依赖于轻简化栽培的关键技术,包括精准播种或轻简育苗技术,经济施肥技术、节水灌溉技术、集中成铃技术等。单粒精播的壮苗机制在于棉花种子萌发出苗时,其弯钩形成关键基因HLS1与COP1和下胚轴伸长关键基因HY5与ARF2的差异表达;密植减免整枝机制在于密植引起棉株激素合成代谢相关基因差异表达,抑制了叶枝的生长;轻简栽培棉花的丰产稳产机制在于棉花产量构成、生物量和经济系数的适应性协同;依据适宜叶面积指数及其动态,适宜株高、节枝比和棉柴比等量化指标,可以有效塑造高光效群体,实现优化成铃和集中成铃与采收;轻简施肥的依据在于棉花对肥料N的吸收集中在开花后20 d以内,初花肥利用效率最高且主要分配到生殖器官;分区灌溉节水机制在于部分根区灌溉诱导地上部合成茉莉酸,茉莉酸又经韧皮部运至灌水侧根系,增强了该侧根系的吸水能力,提高了水分利用率。展望未来,应在深入研究轻简化植棉生理生态学规律的基础上,进一步改革和优化种植制度,创新关键栽培技术,研制新的物质装备,促进农艺技术和物质装备高度融合,为轻简化植棉提供更加有力的理论和技术支撑,推动棉花生产的可持续发展。     

苏北沿海棉区棉花轻型栽培技术

苏北沿海棉区是我省同时也是我国植棉集中、单产较高的商品棉基地。但是近年来随着市场经济体制的不断完善．第二、三产业的发展，植棉相对效益也越来越低．从事植棉的人口和面积也呈下降趋势，在这种形势下．轻型栽培是植棉业发展的必然趋势。轻型栽培其核心思想：一方面节省成本、增加效益，另一方面积极简化一切可以简化的植棉管理工序，     

化学整枝剂对棉花生长的影响

为了开发棉花生产新技术，充分挖掘棉花生产节本增效的潜力。将目前采用人工摘除顶尖和群尖改为使用化学整枝剂抑制生长点的生长．达到一次喷药全面整枝的化学整枝技术，最大限度地简化棉田整枝工序，降低植棉成本，促进棉花生产向质量效益转变。     

简化植棉技术 提高植棉效益

<正>提高植棉效益的途径是努力提高棉花产量和品质并简化操作技术,降低劳动力强度,归根结底一要靠品种,二要靠技术;而品种多乱杂和栽培水平滞后是近年来棉花生产上的突出问题。多是指:品种审定     

棉花优质高产简化栽培技术的探讨

我国棉花生产发展进入了转折性新阶段,不但要求优质商产,而且迫切要求简化栽培、省工省本、经济效益高。我国传统的棉花生产是精耕细作,这是在过去历史条件下形成的,起过重要作用。但与世界先进植棉国家相比,我国的劳动生产率太低。据有关资料介绍:1980～1983年平均,美国棉花单产38.7公斤,每     

规模化种植:河南植棉业高产高效与现代化的方向

河南省棉区的一些植棉大县,棉花规模化种植大户已经占到相当比例。相比之下,植棉大户们的植棉投入充分、采用品种优良、经济实力较强、技术措施到位。所以,棉花产量高,单位产品成本低,收益颇丰。本调查报告,旨在客观如实归纳分析的基础上,仅就河南植棉业高产高效规模化种植经营和现代化发展方向等问题提出意见和建议。1目前,河南棉区棉花规模化种植经营的基本模式棉花的规模化种植经营是相对于分散、小规模和少量种植而言的。目前,河南棉农的户均耕地、植棉面积、单产水平、棉花收益及棉农的专业化生产水平均明显高于其它棉区。其中,几十亩…     

陆地棉滴灌田氮肥经济高效运筹分析

在自然生态条件下,以中棉所49为试材, 分析了6种不同施氮模式（N0、N1、N2、N3、N4、N5）对棉花生育进程、农艺性状、SPAD、LAI及产量构成因素的影响, 探讨了不同施氮模式下棉花种植经济效益。结果表明,在南疆生态条件下,种植滴灌田陆地棉最佳施氮量为N2。该施氮量方式下,棉花农艺性状综合水平优于其它群体,SPAD、LAI表现良好,经济产量高,成本较少。同时,提出种植棉花简化节本的多项指标,为确定棉花高产栽培措施及建立棉花简化节本种植模式提供参考。     

从塔里木灌区棉花生产气候条件探讨其发展对策

对塔里木灌区棉花生产的气象条件进行了简明扼要地分析，发现灌区光照资源丰富，热量资源稍显不足，只适宜早、中熟陆地棉种植。如果通过优选洁白带丝光或天然彩色棉的品种，以追求效益产量为目标，改善棉花气候生态条件和植棉技术，提高单产和品质，充分发挥光照资源优势，可确保本地棉花产业的持续发展。     

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.     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

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.     

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 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.     

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.