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1.
【目的】 研究新疆绿洲干旱区不同棉种主要综合性状,综合评价南疆生产上推广应用的棉花品种,为南疆品种选择和提质增效栽培提供一定的理论依据。【方法】 以新疆南疆棉区历来选育的有代表性的16个品种为材料,分析新疆干旱绿洲区栽培下棉花农艺形状、品质、根系、产量及产量构成因子等主要性状相关性和聚类分析。【结果】 各品种铃重为4.5~6.5 g,单株铃数和产量10-108-3最多,铃数与产量的灰色关联度最大,其值为0.93。籽指与籽棉重、纤维重为显著正相关,相关系数分别为0.492、0.538,衣分与种子数呈显著负相关,相关系数为-0.532。各品种马克隆值为4.62~5.73,比强度与马克隆值呈负相关,与伸长率呈正相关关系。【结论】 总根长与果节始节、果枝数、伸长率呈显著正相关,生育期与子叶节高度、果枝数呈负相关关系,与果节始节、比强度、伸长率呈显著正相关。  相似文献   
2.
Low level of iron in staple food crops is one reason for the predominance of iron-deficiency anemia in developing countries. Most of the iron in rice grains accumulates in the outer aleurone layer and embryo, which are removed during milling, and the edible endosperm contains very low amounts of iron. In an effort to increase iron nutrition, we report here the transgene introgression of a high-iron trait into a high-yielding indica rice cultivar. The ferritin gene from soybean (soyfer1) was introduced into rice plants through interbreeding between soybean ferritin-overexpressing transgenic IR68144 and the high-yielding cultivar Swarna. The stable integration of the soyfer1 gene was confirmed in the BC2F4 generation, and the hybrid seeds showed 2.6-fold soybean ferritin gene expression over the recurrent parent Swarna. The hybrid milled seeds revealed a 2.54-fold increase in iron and 1.54-fold increase in zinc compared to Swarna. Agronomic data and an SSR marker analysis of the hybrid rice plants were taken into account for NIL character identification.  相似文献   
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The major vernalisation genes of VRN1 are well understood at the molecular level. However, their quantitative contributions to flowering time and grain yield related traits are not clear. In this study, we used a double haploid population (225 lines) of Westonia × Kauz in which the Vrn-A1a (Westonia), Vrn-B1a (Westonia) and Vrn-D1a (Kauz) were segregating, and a high resolution genetic map of 1,159 loci, to determine the quantitative contributions of Vrn-A1a, Vrn-B1a and Vrn-D1a for the days to anthesis and grain yield related traits in diverse environments. The major quantitative trait loci (QTL) of spikelet number per spike and days to anthesis were contributed by the winter alleles of VRN1. The QTL of the time of grain filling were contributed by the spring alleles of VRN1. The wild genotype (vrn-A1vrn-B1vrn-D1) showed the latest flowering, the highest spikelet number per spike, lowest peduncle proportion and thousand grain weight in three environmental analyses, and the largest spikelet number per spike, which resulted in high kernel number per spike (KN) and grain weight (GW) in well-watered environments. One QTL of KN was located on 5B, contributed by winter allele of vrn-B1 in three environmental analyses, and one GW QTL was detected on 5A, contributed by the spring allele of Vrn-A1a in a drought environment. The results indicated that the genotype Vrn-A1avrn-B1Vrn-D1a would shorten the time to anthesis and give high GW and KN in drought environments. The early anthesis associated phenotype, peduncle proportion would provide an indicator in breeding programs.  相似文献   
5.
Cold plasma, an ionized gas produced by applying an electrical current to air, can be used to produce plasma-activated water (PAW), which has excellent antimicrobial properties. In this study PAW was applied to conidia of Colletotrichum alienum to investigate its impact on conidial germination in vitro. PAW was produced by treating tap, deionized, or distilled water with cold plasma for 30 or 60 min to produce PAW30 or PAW60, each of which was then incubated for up to 24 hr with a conidial suspension of C. alienum in a ratio of 1:1, 1:2, or 1:3 (conidial suspension:PAW), and the percentage germination measured. The greatest reduction in germination occurred when conidia were incubated with PAW60 produced from deionized water or distilled water, for all ratios. For PAW30, deionized water was the most effective for all three ratios, and on this basis, deionized water was selected for all further experiments. PAW produced from smaller volumes of water and at shorter distances from the cold plasma source was more effective at reducing germination. Treatment of conidia with acidified water was not as effective as PAW at inhibiting germination. Nitrates and nitrites were present in the PAW in varying concentrations and may have contributed to the inhibition of germination. PAW retained activity and reduced germination even after storage for 15 days. These findings demonstrate the potential of PAW as a novel treatment for postharvest fungal pathogens.  相似文献   
6.
Semen from Black Bengal bucks was collected to establish a cooling protocol (to −196°C) for buck semen preservation, and to study the effect of freezing on sperm motility and morphology. Semen was diluted with diluents (Triladyl & Tris) and cryoprotectants, filled into straws, sealed, cooled (to 5°C) and equilibrated. After dilution, motility ranged from 75.00% to 76.67% and from 73.33% to 80.00% in Triladyl and Tris diluents, respectively. Motility of sperm after cooling to 5°C in Triladyl and Tris diluents ranged from 65.00% to 66.67% and from 63.33% to 70.00%, respectively. After equilibration in straws, the semen was subjected to a freezing protocol in a computer-controlled biofreezer CL-3000 (cooling at 10°C per minute, from 5°C to −80°C) and plunged into liquid nitrogen. Sperm motility of re-thawed semen varied from 38.33% to 43.33% and from 6.00% to−6.67% in Triladyl and Tris diluents, respectively. Sperm morphology of re-thawed semen was studied and head damage or cryoinjury was found in 2–3% of sperm in Triladyl diluents and 3–6% in Tris diluents. Whether the differences of sperm motility and head damage reflect fertility after artificial insemination is yet unknown and needs to be studied further.  相似文献   
7.
Juri is a biodiversity-rich primary forest in Bangladesh, which remains ecologically unexplored. We identified tree species and examined the richness, alpha(a)diversity and floristic similarity patterns within the identified communities. Vegetation and environmental data were sampled in 120(0.04 ha) study plots. Tree communities were delimited by two-way indicator species analysis(TWINSPAN). In total, 78 tree species of 35 families and58 genera were identified. TWINSPAN identified six tree communities: A—Tricalysia singularis; B—Kydia calycina-Castanopsis tribuloides; C—Polyalthia simiarum-Duabanga grandiflora; D—Ficus roxburghii; E—Artocarpus lacucha; F—Artocarpus lacucha. Mean richness, Shannon and Gini-Simpson indices were highest for the Polyalthia simiarum-Duabanga grandiflora community, while Ficus roxburghii showed lowest diversity. Significant differences(p = 0.05) in three diversity indices were recorded between Polyalthia simiarum-Duabanga grandiflora and Ficus roxburghii. Tree compositional similarity was greatest between Kydia calycina-Castanopsis tribuloides and Polyalthia simiarum-Duabanga grandiflora(0.712).  相似文献   
8.

Routine monitoring for subclinical infection is one of the key mastitis control approaches. However, the accuracy of the most commonly used screening tests has not yet been established. The aim of the present study was therefore to evaluate the accuracy of three screening tests, namely California mastitis test (CMT), white side test (WST), and surf field mastitis test (SFMT) for the screening of subclinical caprine mastitis. A cross-sectional study based on 484 randomly collected milk (242 goats) samples from three districts of Bangladesh was conducted for the screening of subclinical mastitis by the aforementioned tests. The Bayesian latent class model was implemented in WinBUGS to estimate the tests’ characteristics and true prevalence of subclinical mastitis. The Bayesian posterior estimates of sensitivities with a 95% credible intervals (CrIs) were 98.60% (95.18–99.95%), 98.28% (94.56–99.92%), and 89.98% (83.39–95.03%), and specificities with 95% CrIs were 99.19% (98.11–99.96%), 99.27% (97.34–99.98%), and 99.28% (97.35–99.98%), respectively for CMT, WST, and SFMT. The true prevalence of subclinical caprine mastitis was estimated to be 43.49% (95% CrI 37.46–48.98%). The positive predictive values (PPV) of the three tests were similar. The serial and parallel interpretation of any test pairs increased the PPV and negative predictive value respectively close to 100%. Based on the simplicity, cost and performance as well WST and SFMT simultaneously could be recommended for the screening of caprine subclinical mastitis in Bangladesh.

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9.
Summary

Seasonal fluctuations of carbohydrate composition and concentrations, and the activities of related enzymes of three domesticated tomato cultivars including two large (Lady First and Momotaro) and one cherry-fruited (Minicarol) cultivar were examined at 45 d interval with seven sowing times. Fruits picked in cool seasons (early winter to spring seasons) had higher sugar concentrations than those of warm seasons. Fructose and glucose in nearly equal amounts were the predominant sugar in all seasons. Sucrose was present in trace quantities, but cherry tomato cultivar ‘Minicarol’ accumulated more than the large fruited types. Acid invertase (AI) (EC 3.2.1.26) activity was highest during cool seasons at the red stage of ripening, while fruit matured during warm seasons (May to August) had lowest activity. The sucrose synthase (SuSy) (EC 2.4.1.13) showed significantly higher activity during cool seasons in rapidly growing fruits followed by very low activity in mature non-growing fruits. There were no significant differences in sucrose phosphate synthase (SPS) (EC 2.4.1.14) activity. A highly significant positive correlation was found with sucrose accumulation in the case of SuSy but there was a negative correlation with AI activity and none with SPS. Therefore, in all growing seasons, AI and SuSy, rather than SPS could play a central role in regulating sugar accumulation in both large and cherry tomatoes. The result suggested planting season had no adverse effect on the trends of carbohydrate accumulation and metabolism in developing tomato cultivars, but in cool-season crops there is an improvement in fruit carbohydrate accmulation with more enhanced enzyme activities than in warm-season crops. These observations may help in selecting molecular genetic targets, and provide information for biotechnologists who wish to improve desired quality criteria of domesticated tomato genotypes.  相似文献   
10.
在大豆-玉米轮作生产过程中,玉米杂苗会与大豆苗竞争水和肥料,而且很容易遮住大豆苗,影响害虫(如玉米根虫)的防控,降低大豆品质。因此,在大豆幼苗期及时检测出玉米杂苗并对其进行处理非常重要。传统的人工检测方法主观性强、效率低,传感器和算法的发展为自动检测玉米杂苗提供了更好的解决方案。本研究在温室环境下模仿田间条件,待玉米和大豆发芽后,连续5天用因特尔RealSense D435相机采集彩色图像,并人工裁剪幼苗图像区域,在此基础上对图像进行分割和去噪。在采集图像形状、色彩和纹理特征值后, 对所采集的特征值进行权重分析, 保留前10种重要的特征值导入基于特征的机器学习算法中进行模型训练和预测。预测结果表明,支持向量机模型(SVM)、神经网络(NN)和随机森林(RF)的预测精度分别为85.3%,81.5%和82.6%。将数据集导入GoogLeNet和VGG-16 两种深度学习模型进行训练, 预测精度分别为96.0%和96.2%。VGG-16 模型在区分大豆幼苗和玉米杂苗中有较好的表现,彩色图像和VGG-16 模型组成的系统可以自动检测大豆生长过程中玉米杂苗的情况,为农民提供准确的信息,帮助其进行生产决策和田间管理。  相似文献   
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