陆地棉品种间杂种F_2代优势研究及经济农艺性状的通径分析

用７个Ｆ１代具高竞争优势的陆地棉品种间杂种Ｆ＿２代和高产、优质、多抗的品种鄂棉１５（对照）为材料，研究了Ｆ＿２代及皮棉产量等经济性状的竞争优势，又对它们与株高等在艺性状进行了通径分析。结果表明：正确选配亲本，能将高产、优质、早熟综合于一体，多代利用陆地棉品种间杂种。３８４×３６１Ｆ＿２，鄂荆１号（３２４７）×３６１Ｆ２显著优于对照，分别增产１５．４９％、１２．１６％，且纤维长度、早熟性与对照相近，在生产上有很大的利用价值。决定Ｆ＿２代皮棉产量主要是单株铃数、衣分以及它们之间的互作。同一农艺性状对不同经济性状影响程度很不相同，每个经济性状一般都受１～３个主要农艺性状和它们之间，或它们与其他农艺性状互作所制约。在湖北生态条件下，高产、优质、早熟的陆地棉品种间杂种Ｆ＿２代应具备棉抹较高，果位适中而果高偏低，纵横比较大，果枝夹角较小及主茎节距较大等农艺性状     

氮沉降对湿地松林土壤呼吸的影响

为了阐明湿地松林土壤呼吸对氮沉降响应的变化规律以及氮沉降是否改变土壤呼吸温度敏感性系数,运用LI-8100开路式土壤碳通量测量系统测定模拟氮沉降4种不同处理水平[0、5、15、30 g/(m2?a)]下湿地松林(Pinus elliottii)的土壤呼吸速率及土壤温、湿度。结果表明：湿地松林土壤胡须呈明显季节变化,7月最高,1月最低。各处理土壤呼吸年累积量为：对照(CK)[5.28±1.02 t/(hm2?a)]、低氮[LN 4.51±0.64 t/(hm2?a)]、中氮[LN 4.66±0.51 t/(hm2?a)]和高氮[HN 4.20±0.43 t/(hm2?a)]。全年对照处理土壤呼吸速率平均值为CK[1.44±0.28 μmol/(m2?s)]比各氮沉降处理LN[1.20±0.17μmol/(m2?s)]、MN[1.24±0.13μmol/(m2?s)]、HN[1.11±0.11μmol/(m2?s)]高16.6%、13.8%、22.9%。土壤呼吸速率与10 cm土壤温度呈显著相关正指数关系(P<0.01),相关性指数(R2)在0.6049~0.7557之间,湿地松林在各处理氮沉降下温度敏感性系数分别为LN(1.72)、MN(1.75)、HN(1.79)同对照(2.35)相比有降低趋势。土壤呼吸与5 cm土壤湿度之间呈二次方程关系,但相关性不显著(P>0.05)。研究表明,氮沉降是影响湿地松林CO2通量的一个重要因子。     

Response of soil respiration to nitrogen addition in two subtropical forest types

Anthropogenic activities have increased nitrogen (N) deposition in terrestrial ecosystems, which directly and indirectly affects soil biogeochemical processes, including soil respiration. However, the effects of the increases in N availability on soil respiration are not fully understood. In this study, soil respiration was measured using an infrared gas analyzer system with soil chambers under four N treatments (0, 5, 15, and 30 g N m^-2 year^-1 as control, low N (LN), moderate N (MN), and high N (HN), respectively) in camphor tree and slash pine forests in subtropical China. Results showed that soil respiration rates decreased by 37% in the camphor tree forest and 27% in the slash pine forest on average on an annual base, respectively, in the N-fertilized treatments when compared with the control. No significant differences were found in the soil respiration rate among the LN, MN, and HN treatments in both forest types as these fertilized plots reached an adequate N content zone. In addition, soil microbial biomass carbon (C) content and fine root biomass declined in N-treated plots compared to the control. Our results indicated that elevated N deposition might alter the tree growth pattern, C partitioning, and microbial activity, which further affect soil C sequestration by reducing soil respiration in subtropical forests of China.     

43份黄秋葵种质的ISSR分析

对Owayadei(Abelmoschus esculentus L.)、Ladies fmger(Abelmoschus esculentus L.)、golder kost(Abelmoschus esculenats L.)、Esoyafido(Abelmoschus esculentus L.)等42个国内外黄秋葵栽培种和野生黄葵(Abelmoschus moschatus Medicus Malv.)进行ISSR分析.结果表明,选用22条引物扩增出306条DNA片段,平均每个引物可扩增出13.9条片段,其中多态性片段271条,占扩增总片段的88.6%.利用扩增结果进行遗传距离分析,构建分子树状图,可把42份黄秋葵栽培种质和野生黄葵分开,同时,可将42份黄秋葵栽培种质材料划分为2个类群.     

棉花γ_2代性状间的相关性研究 Ⅰ棉花γ_2代主要经济性状间的相关分析

以高产品种鄂棉１５γ２代与品系０５①００６γ２代的正常型、非正常型及相应的未辐射材料为试材，研究了它们的皮棉产量等６个主要经济性状间的相关性。结果表明：辐射能显著地改变棉花数量性状间的相关，明显地表现在经济性状间相关的改变上，但依不同的基因型而异。在γ２代正常型中，能选出高产、优质、早熟于一体的单株，解决了常规育种难以融三者于一体的问题。在鄂棉１５γ２代的正常型中，选择结铃性强的单株，可以较好地协调产量组分间的关系，将高产、优质、早熟结合起来；但是在０５①００６γ２代的正常型中选株则要注意协调产量组分间的关系。γ２代非正常型的植株难以协调产量组分间及其与高产、优质、早熟之间的关系。     

Rapid evolution of Ophraella communa cold tolerance in new low-temperature environments

Low winter temperatures severely stress newly arriving insect species. Adaptive evolutionary changes in cold tolerance can facilitate their establishment in new environments. Ambrosia artemisiifolia, a noxious invasive plant, occurs throughout China. Ophraella communa, a biological control agent of A. artemisiifolia, mainly occurs in southern China. However, in 2012, it established populations in Beijing (39.98°N, 115.97°E) following introduction from Laibin (23.62°N, 109.37°E), implying cold adaptation. The mechanisms underlying its rapid evolution of cold tolerance remain unknown. We investigated the levels of cryoprotectants and energy reserves in adult O. communa from two latitudes. In high-latitude insects, we found high trehalose, proline, glycerol, total sugar, and lipid levels; five potential genes (Tret1a, Tret1b, Tret1-2, P5CS, and GST), responsible for regulating cold tolerance and involved in trehalose transport, proline biosynthesis, and glutathione S-transferase activation, were highly expressed. These hybridisation changes could facilitate cold temperature adaptation. We demonstrate the genetic basis underlying rapid adaptation of cold tolerance in O. communa, explaining its extension to higher latitudes. Thus, specialist herbivores can follow host plants by adapting to new temperature environments via rapid genetic evolution.

     

沛县鸭传染性浆膜炎的病原分离鉴定及药敏试验

收集沛县具有典型鸭传染性浆膜炎症状的34份病死鸭进行细菌的分离培养。总共得到18株疑似鸭疫里默氏杆菌（RA）,从中随机选取10株RA进行生化鉴定及动物回归试验,经确认后使用本地区常见的抗菌药进行了纸片法药敏试验,结果发现RA分离菌株对头孢噻肟、氧氟沙星、阿莫西林＋棒酸等药物敏感度较好,对氟苯尼考、丁胺卡那、阿奇霉素等药物敏感度很低。研究结果为该地区鸭传染性浆膜炎的药物防治提供了很好的理论依据。     

棉花“两高一优”的栽培策略

以品种区试结果和示范推广的栽培研究为依据,阐述了鄂棉１５的生育特点、高产的产量结构及农艺指标,从而论述了棉花“选用良种、两膜栽培、合理密植、巧肥精管、全程化调”为主要内容的“两高一优”栽培策略,建立了当前棉花大田生产的栽培模式。     

晴转阴天气日光温室内环境因素日变化研究

研究了黄瓜日光温室在晴转阴天气条件下的温度，相对湿度，光照强度和ＣＯ２浓度等环境因素的日变化以及黄瓜光合速率的日变化，黄瓜日光温室在该天气条件下具有温度较低，光照弱，光合速率正常情况减少１／２以上等特殊性，指出光照强度有限制因子，并提出了生产中应采取的相应措施。     

不同抗旱性柱花草品种在高渗溶液中的萌发特性

利用PEG高渗溶液法研究不同抗旱性柱花草品种的萌发特性。结果表明：除质量浓度为100g/L的PEG对热研2号和热研10号的种子萌发有轻微的促进作用外,其余质量浓度PEG对种子的萌发、胚芽和胚根的生长都有抑制作用。胚根抑制率和根芽比的变化幅度基本反映了柱花草的抗旱性,可作为抗旱性评价的参考指标;质量浓度为250 g/L的PEG处理下的相对根芽比差异非常显著,可作为柱花草抗旱性评价的可靠指标。