首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 406 毫秒
1.
甜玉米的生育特点及实践应用   总被引:2,自引:0,他引:2  
甜玉米为玉米种中的一个亚种(Zea mays saccharata),是隐性基因(su1或sh2)控制的,乳熟期籽粒中的蛋白质、赖氨酸、色氨酸、矿物质及脂肪等含量均高于普通玉米。甜玉米用途广泛,经济效益很高。  相似文献   

2.
椰心叶甲发育的起点温度和有效积温   总被引:8,自引:0,他引:8  
通过室内饲养观察,测定了不同温度下椰心叶甲不同虫态发育的起点温度、有效积温及存活率。结果表明,椰心叶甲世代发育起点温度为11.08℃,有效积温为966.22℃,在海南省儋州市1a发生的理论代数为4~5代。持续过高温度,如32℃不适宜椰心叶甲的生长。  相似文献   

3.
干旱对甜、糯玉米幼苗生长和生理指标的影响研究   总被引:5,自引:1,他引:5       下载免费PDF全文
杨勤  刘永红 《玉米科学》2005,13(1):072-076
采用盆栽称重控水法,对甜、糯玉米播种出苗期进行水分胁迫试验.结果表明,土壤干旱直接影响叶片相对含水量、干物质积累速度、叶面积、净同化率和叶绿素含量等指标,导致植株生长缓慢.但一定程度的干旱(本研究土壤相对含水量为20%~40%)有利于根系下扎,增大根冠比和叶绿素a的比重,增加脯氨酸(Pro)的积累量.同时,甜玉米种子供给营养能力弱,1叶全展后,必须加强水分管理,否则干旱胁迫影响加剧,但成苗后甜玉米的耐旱能力强于糯玉米。  相似文献   

4.
优质青贮玉米品种龙青1号的选育及栽培要点   总被引:3,自引:5,他引:3  
龙青1号青贮玉米品种是黑龙江省农科院玉米研究中心以自育系H220为母本,引入自交系G219为父本杂交育成的单交种。该品种从出苗到适宜采收期(蜡熟期)需有效积温2550℃.d左右,在哈尔滨市生育日数为115~120d。2000~2003年在各级试验中表现为优质、高产、稳产、抗病、抗逆性强等特点。龙青1号青贮玉米品种适宜在黑龙江省第一积温带下限和第二积温带种植,密度为60000株/hm2左右。  相似文献   

5.
基于SSR标记构建甜玉米群体的核心种质   总被引:1,自引:0,他引:1  
利用40对SSR引物分别分析56份超甜玉米和88份普甜玉米群体材料,基于非加权算术平均配对法(UPGMA)聚类分析和位点优先取样法,分别筛选出14个超甜玉米核心材料和19个普甜玉米材料作为两个亚群体种质。t测验表明,两个亚核心种质与原始群体的等位变异无显著差异(P0.05),等位变异保留率分别为87.81%和89.13%,有效地保留了原始材料群体的遗传变异。两个亚群核心种质与原始材料群体13个表型性状的均值、标准差、极差、变异系数和Shannon-Weaver多样性指数(H’)的平均符合率都在80%以上,并且均值差异百分率(MD)和方差差异百分率(VD)均小于20%,极差符合率(CR)和变异系数变化率(VR)均大于80%,符合核心种质的质量评价标准。构建的甜玉米核心种质最大程度地保留了原始群体的遗传多样性和表型变异,能够有效地代表原始甜玉米材料群体。  相似文献   

6.
就广义讲,薪鲜市场鲜食玉米包括籽粒幼嫩、其全部糖分尚未转变成淀粉即收获鲜食的所有玉米。该定义还包括大田玉米选育中的烤玉米,这种玉米缺乏增甜基因而是粉质型。但传统上甜玉米品种为纯合的稳性甜质(su)基因。许多新甜玉米种拥有控制籽粒甜度特性的独特基因组合。这些基因可单独使用,或与其它各种甜质基因(su)相结合,后者包括皱  相似文献   

7.
范锦胜 《玉米科学》2007,15(Z1):016-017
优质青贮玉米中北410是山西北方种业优质玉米所以SN915为母本,YH-1为父本杂交育成的单交种。该品种从出苗到适宜收获期(乳熟后期至蜡熟前期)需有效积温3 081.2℃.d左右,东北华北春玉米地区出苗至青贮收获111 d,比对照农大108晚3~5 d。在各级试验中表现为优质、高产、稳产、抗病、抗逆性强等特点。青贮玉米中北410适宜在北京、天津、河北北部、山西北部春玉米区及河北中南部夏播玉米区、福建中北部用作专用青贮玉米种植。矮花叶病高发区慎用。  相似文献   

8.
超甜玉米生产性能模糊综合评价   总被引:1,自引:0,他引:1  
应用模糊综合评价方法,对2003~2004年全国超甜玉米区试新组合的6个生产性能进行了定量化评价。结果表明:①用模糊数学综合评价能够将多种性状指标归纳为一个统一的量化综合评价指标(模糊综合指数,FCI),该指标能较好地反映各新组合的实际综合生长性能水平,所获得的最终评价值不仅能反映各评价单元之间的相对级别,而且能直接反映它们的绝对等级。②根据FCI划分为5个综合评价等级,绝大多数超甜玉米新组合(或品种)处于3~4级。我国超甜玉米新品种选育需要种质资源的创新和选育水平的提高。  相似文献   

9.
甜玉米速冻加工技术研究   总被引:3,自引:0,他引:3  
1994~1996年我们进行了甜玉米速冻加工技术研究。结果表明,甜玉米速冻加工保鲜期达6~8个月的关键技术是:鲜穗适采期为授粉后24~27d;漂烫比蒸煮效果好,时间为18min,冷点温度≥90℃;速冻温度为-38~-45℃;贮藏温度为-18℃。  相似文献   

10.
中熟玉米杂交种酒单289选育报告   总被引:1,自引:0,他引:1  
酒单289由甘肃省酒泉地区农科所玉米组育成,组合为酒11—2×TS31。该品种属中熟玉米品种。从播种至成熟需≥10℃有效积温2650℃。1988~1994年在各类产量试验中表现稳产、抗病.在适宜密度69000株/hm2下比对照酒单3号增产14.5%。酒单289农艺性状优良,高抗丝黑穗病,中抗大斑病.适宜在河西走廊地区的沙漠绿洲地域及陇东平凉、甘肃中部地带的清水种植.制种产量可达4500kg/hm2,制种父母本行比1:5。  相似文献   

11.
12.
Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.  相似文献   

13.
Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.  相似文献   

14.
15.
Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.  相似文献   

16.
Novel food and non-food uses for sorghum and millets   总被引:4,自引:3,他引:4  
Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.  相似文献   

17.
Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.  相似文献   

18.
Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X1 (also called RXact).  相似文献   

19.
The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O2•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O2•− scavenging, (IC50 = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC25 = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC50 = 863 µg/mL; elastase, IC50 = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O2•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms.  相似文献   

20.
The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号