基于网格控制容差的屏幕数字化在土地利用分类上应用的研究

本文对基于网格控制容差的屏幕数字化的有关理论和方法进行了探讨。试验表明采用屏幕数字化,即采取人机交互的方式,将RS和GIS,专家知识和目视解译结合起来进行地物识别,是一种分类精度较为准确的方法。     

全球水稻分子育种计划核心种质苗期耐低磷资源的鉴评与筛选

苗期低磷胁迫水培试验表明 :全球水稻分子育种计划核心种质对低磷营养胁迫的调节能力存在着显著的基因型差异 ,表现在分蘖能力、根长、根重等性状明显不同。通过对低磷营养胁迫下水稻根茎性状表现的评价 ,筛选出耐低磷品种资源     

一个新的拟南芥磷饥饿反应突变体筛选体系

磷是植物必需的一种大量营养元素。农作物的产量经常因磷饥饿而受损。研究植物在磷饥饿 条件下所发生的变化,有利于以后运用基因工程的手段培育耐低磷农作物。将野生型拟南芥与磷饥 饿反应突变体进行对比研究,能够为植物对磷饥饿反应的研究提供重要线索。筛选植物对磷饥饿反 应突变体,筛选方法是非常重要的。野生型拟南芥在供磷正常的培养基上竖直培养时主根向下,同时 呈较大幅度的弯曲。在磷饥饿的培养基上主根则几乎是垂直向下的,而且主根相对较为短小。利用这 种现象,在供磷正常的培养基上种植的拟南芥植株中发现了一株可能的新的磷饥饿反应突变体。     

番茄内生真菌的分离和拮抗生防菌的筛选

采用内生菌常规分离法对健康番茄植株体内的内生真菌进行了分离和筛选。结果表明: 番茄的不同品种不同部位内生真菌的数量有所不同, 同一品种茎部比根部种类多。经初步鉴定, 除1种属于子囊菌外, 其余均为半知菌。拮抗结果表明: 无孢菌、曲霉对灰霉和菌核病菌均有较强的抑制作用, 产生明显抑菌带。其它部分菌株对病原菌均有不同程度的抑制作用。无孢菌Fq72菌株培养滤液活性测定结果表明: 其培养滤液对6种病菌均有不同程度的拮抗作用, 尤其对菌核病菌和灰霉病菌抑制率最高, 而且其培养滤液高温处理后活性不丧失, 对病菌仍有较强的拮抗作用, 因此其具有一定的生防潜能。     

番茄青枯病菌拮抗细菌的筛选及鉴定

[目的]筛选出番茄青枯病菌的拮抗细菌,为番茄青枯病的防治提供参考.[方法]从番茄青枯病发病田块中的无病植株根际土壤中筛选获得拮抗细菌,通过形态和培养特征的观察、生理生化的测定和16S rDNA系列分析鉴定其分类地位,并通过盆栽试验验证其防效.[结果]从湖南省张家界市采集的番茄田土壤在NA培养基中分离出104株细菌,有6株细菌对青枯病菌有拮抗活性,其中1株拮抗菌菌株88号对青枯病病原菌有较强拮抗效果,抑菌圈达7.2 mm,其发酵液温室盆栽防效达96.4％,该菌株初步认定为伯克氏属(Burkholderiasp.).[结论]菌株88号在防治番茄土传病害上具有很好的应用前景.     

防治台湾白柚枝枯病药剂的筛选

台湾白柚枝枯病是柑橘类病害的一种,其病原物是半知菌亚门丝孢纲瘤座孢目镰孢菌属镰刀菌,以尖镰孢为主。通过药剂筛选表明:50%甲基硫菌灵1 000倍液5、3.8%可杀得1 000倍液、扑菌特1 200倍液和70%宝福斯1 000倍液均对病原物的孢子和菌丝生长抑制效果显著,53.8%可杀得1 000倍液的效果尤为明显。该试验为生产中台湾白柚枝枯病的化学防治提供了理论依据。     

甘肃省中部地区冬小麦品种(系)筛选

[目的]了解甘肃省中部地区冬小麦品种(系)的适应性和丰产性,为筛选适宜该地区种植的冬小麦种质提供依据。[方法]通过田间观察、物候期记载、农艺性状调查和产量统计分析,筛选适宜该地区种植的冬小麦品种(系)。[结果]200707-3、静冬0318生育期适中,籽粒饱满,产量较高,分别较对照陇中1号高32.98%和30.18%,抗逆性强,丰产性好。[结论]200707-3、静冬0318综合性状表现好,适宜在甘肃省中部地区推广种植。     

鲜食玉米品种的筛选

[目的]筛选适宜在武汉及周边地区推广应用的鲜食玉米品种。[方法]引进彩甜糯6号、鲜玉糯4号、万糯2000等10个鲜食玉米品种,进行对比试验。[结果]彩甜糯6号、鲜玉糯4、万糯2000、信彩甜糯1号4个品种的产量显著高于其他品种,而且感官等级和蒸煮品质也高于其他品种。[结论]彩甜糯6号、鲜玉糯4、万糯2000、信彩甜糯1号适合在武汉及周边地区推广种植。     

辣椒疫霉病生防细菌的筛选鉴定及其防效

以筛选、获取优良辣椒疫霉病害生防菌株材料为目标,通过平板稀释法与对峙法对水稻土壤耕层可培养细菌进行 分离和筛选,成功从167 株可培养细菌中分离、筛选获得1 株拮抗菌LRS-1,并被鉴定为多粘类芽孢杆菌（Paenibacillus polymyxa）。该拮抗菌对辣椒疫霉菌具有68% 左右的室内持久抑菌率以及63.4% 的温室病害防效;Realtime-PCR 检测结果表 明该拮抗菌对根围疫霉菌侵染数量具有显著的抑制效果。     

Urban green spaces for children: A cross-sectional study of associations with distance,physical activity,screen time,general health,and overweight

This study investigates the associations between: (i) urban green spaces (UGSs), children‘s frequency and duration of physical activity (PA), and screen time (TV viewing and computer use) and (ii) children‘s frequency and duration of PA and their general health and overweight. In this study, ‘children’ includes both younger children and adolescents, ages 1–18. Parent-reported data (n = 422) collected though face-to-face personal interviews between April 1 and May 31, 2015 in the city of Aydin, Turkey were used in the study. Multivariate regression analyses were conducted to examine the associations controlling for children’s sex, age, and parents’ monthly income. Stratified analyses were also conducted to determine differences between sex (boys and girls) and age (1–6, 7–12, and 13–18 years old) groups of children. The findings showed that UGS closeness to home was positively associated with higher frequency of children’s PA (b = −.22, p ≤.001) and less screen time (b = .18, p ≤.001). Results also revealed that children‘s frequency of PA positively correlated with children‘s general health (b = .08, p ≤.05), whereas overweight was associated with only age. In stratified analyses, nearest distance to UGSs was positively associated with both boys‘ and girls‘ frequency of PA. On the other hand, longer distance to UGS was associated with longer screen time for only girls. In regard to age groups, nearest distance to UGSs was related to higher frequency of PA for 1–6 and 7–12 years old, while nearest distance to UGS was associated with longer duration of PA and less screen time for only children ages 7–12. In age groups 13–18, no significant differences between variables of UGSs, PA and health were documented. No sex and age groups showed any significant associations with general health and overweight. The findings of this study suggest that distance to UGSs is important for children‘s PA, screen time, and general health. This study implies that UGSs do not seem to be associated with PA and general health in older age groups and needs further investigations.