搞好基地建设是黑龙江省垦区发展优质米产业的基础

从市场份额、品牌特色、产品质量上界定了黑龙江省优质米开发还处于初级阶段;从个体户种植规模小、品种杂、稻谷质量无法控制上论述了基地建设的必要性;同时指出了基地建设的必要条件,目前“定点企业、定点基地”已成为当地利用特有的自然环境形成优质米生产基地的成功模式。     

Genetic diversity and differentiation of <Emphasis Type="Italic">Camellia sinensis</Emphasis> L. (cultivated tea) and its wild relatives in Yunnan province of China,revealed by morphology,biochemistry and allozyme studies

We evaluated morphological, isozyme and biochemical diversity of a total of 87 accessions in the genus Camellia [Camellia sinensis var. sinensis (10), C. talinensis (7), C. sinensis var. dehungensis (3), C. crassicolumna (3) and C. sinensis var. assamica (64)]. Great variation of morphological characters was apparent within each taxa. Across the five taxa, all leaf and most flower quantitative characters showed significant differences while all fruit quantitative characters measured did not differ significantly, and, seven (i.e., life form, bud color, petal texture, pubescence on ovary, style number, stamen location and locule per fruit) of the 33 qualitative characters yield significant differences. As a whole, caffeine content had the highest variation with CV of 22.7%, water extract solid showed the least variation (13.4%) and content of polyphenols (20.0%) and free amino acids (18.8%) showed intermediate variations. Camellia taliensis and C. sinensis var. assamica had significantly higher content of polyphenols and water extract solid than in the other three taxa, while no significant differences were detected for the content of caffeine and free amino acids. For allozyme study, 14 loci presented good resolution, among which, nine loci (64%) were polymorphic in each taxon (AAT-3, FUM-1, 6PDG-1, G6PDH-1, G3PDH-1, ME-1, PGM-1, PGM-2 and SKD-1). The percentage of polymorphic loci (P) for each taxon was 21.4–50.0%. Mean heterozygosity per locus (H _e ) varied 0.114–0.218. F _ST value indicated that only 4.6% of the variations could be ascribable to genetic differences among taxa. Genetic relationships among the five taxa revealed by allozymes, were also exposed by the result of clustering of the morphological and biochemical characters.     

Establishment of feather follicle stem cells as potential vehicles for delivering exogenous genes in birds

The present study was performed to develop a culture system for feather keratinocyte stem cells to enable the genetic manipulation of endangered avian species. The feather follicle cells were isolated from growing feathers of adult White Leghorn chicken. Leukemia inhibitory factor (LIF) was used to maintain the characterization of the keratinocyte colony-forming cells (KCFCs). The EGFPN1 plasmid DNA retroviral vector was used to deliver Green Fluorescent Protein (GFP) gene, which was introduced to the KCFCs by lipofection. After removal of the fibroblast-like cells, the feather KCFCs attached to the substrate within 24 h of seeding. The cells continued to proliferate for at least 30 days in the presence of LIF. The cell-adhesion molecules such as integrin beta1 and CD49c were immunocytochemically positive in the cells. The KCFCs differentiated into barbular cells and pennaceous feather vane in the LIF-free medium. The GFP gene-transfected KCFCs stably expressed GFP. The present results indicate that the KCFCs derived from feather follicles are closely related to multipotent stem cells. In addition, gene manipulation of such stem cells may be useful for the production of chimera in avian species.     

抑制氧化刚果红光度法测定饲料中牛磺酸含量

在pH为11.0氨-氯化铵缓冲溶液中,痕量牛磺酸能抑制高锰酸钾氧化刚果红的反应,使体系吸光度明显减小,据此建立了分光光度法测定饲料中牛磺酸含量的方法。结果表明:最大褪色波长为670 nm,牛磺酸质量浓度为0～0.5μg/mL时与体系褪色程度呈良好的线性关系,表观摩尔吸光系数为1.94×105L/mol.cm,检出限为7.84μg/L。此方法用于测定饲料中牛磺酸含量,结果与高效液相色谱法一致,标准偏差为0.66%～1.01%(n=6),回收率为97.3%～101.7%。     

非离体条件下荔枝叶片面积的测定方法

通过测定妃子笑荔枝叶片的实际面积(S)、叶长(a)和叶宽(b),经过矫正系数(叶片实际面积与叶长、叶宽乘积的比值)的计算和线性回归分析,构建了妃子笑荔枝叶片面积估算公式:S=0.65ab,S=0.6488ab+0.0018。验证结果表明,上述2个公式均能准确地估算出妃子笑荔枝的叶片面积。     

冰糖橙胚性愈伤组织的诱导与植株再生

以冰糖橙成熟果实中的未发育胚珠为外植体，培养诱导胚性愈伤组织并进行植株再生。结果表明：在不同的培养基和不同的培养条件下胚性愈伤组织和胚状体的发生频率不同；麦芽提取物和GA3有利于胚性愈伤组织的发生，暗培养有利于胚性愈伤组织的诱导；在MKBN(MT KT0．5mg／L BA0．5mg／L NAA0．1mg／L)培养养基上，胚状体的再生率达88．24％，以酸橙作砧木进行试管嫁接，嫁接成活率达88．89％。     

县级现代农业信息服务平台建设

通过对县级农业信息服务平台网络的介绍,进一步突出了农业信息服务对发展现代农业的重要性。     

云南省玉米白斑病病原菌鉴定与品种田间抗性评价

为明确近年来云南省严重发生的玉米白斑病病原菌及不同玉米品种对玉米白斑病的抗性差异,2021年于云南省昆明市阿子营乡和曲靖市罗平县九龙镇采集病样,进行病斑组织分离纯化,通过形态学特征和分子生物学方法对病原菌进行鉴定,并在云南省曲靖市罗平县九龙镇采用田间自然发病方法对622份玉米品种的抗性进行鉴定。从2个采样地点的病叶中各分离出5株和9株菌株,经柯赫氏法则验证,确定了菌株WS-1、WS-191为白斑病致病菌;经形态学观察以及基于ITS、rpb2、tub2和LSU基因序列构建的系统发育树分析结果确定其分类学种名为宽颈附球菌Epicoccum latusicollum。田间抗病性试验结果表明,在622份区域试验品种中对白斑病表现高抗、抗病、中抗、感病和高感的品种分别为4、184、216、186和32份,分别占品种总数的0.64%、29.58%、34.73%、29.90%和5.14%。     

基于粒子群算法和支持向量机的黄花菜叶部病害识别

使用数字图像处理技术,以黄花菜叶部病害图像为识别对象,基于Lab空间和K-means聚类算法分割病害区域,提取目标区域的颜色特征、方向梯度直方图(histogram of oriented gradient,HOG)特征和形状特征,分别建立单一特征模型和特征融合模型,采用粒子群(particle swarm optimization,PSO)算法通过交叉验证优化支持向量机(support vector machine,SVM)模型的惩罚因子和核参数,建立基于PSO-SVM的多特征融合分类模型识别黄花菜病害。基于SVM的多特征融合分类模型识别率高于单一特征分类模型,识别率可达为81.67%;基于PSO-SVM多特征融合分类模型识别率高达92.39%。基于PSO-SVM的多特征分类模型识别率高,可以及时、便捷、高效地识别黄花菜病害。     

安溪铁观音成本-价格调查分析

福建是乌龙茶的原产地,安溪铁观音是乌龙茶精品。本文以安溪铁观音茶农户、茶叶企业、中国茶都-安溪茶叶交易市场等实地考察为依据,对安溪铁观音茶叶生产成本与价格进行了深入细致地调查分析。分析表明：安溪铁观音生产成本构成复杂,包括鲜叶种植成本、初加工成本、精加工成本;在各项成本中,鲜叶生产成本最高;在总成本中,人工成本所占的比例最大。而在价格的调查分析中发现,茶农户的毛茶价格远比茶叶批发商和茶叶店零售价格低,销售成本占销售价格的比例很大。