社会工作视野下高校和谐教育的构建

基于对我国当前高校不和谐现状的分析,秉持社会工作的理念和视角,探索了我国高校和谐教育的含义,并就社会工作作为一种专业方法在建设高校和谐教育中的策略进行了探讨与创新.     

苜蓿冠层温度与农艺性状的相关分析

对从国内外引进的31个苜蓿品种分枝期—结英期的冠层温度及其农艺性状指标进行了相关分析和偏相关分析。结果表明，苜蓿冠层温度与分枝期和现蕾期的茎叶比、开花期的叶面积和产量间存在显著的偏相关关系，可作为产量高低的间接或直接指标；由于农艺性状指标间互相关的影响，冠层温度与农艺性状指标间的单相关系数可靠性差，且与偏相关系数有明显的差异；排除农艺性状指标间互相关影响后，偏相关系数可靠性大，可作为变量间关系密切程度的量化指标。     

新疆石河子地区沙漠增温效应对绿洲农业影响的研究

由于沙漠 ,绿洲 ,空气的比热等热性能不同 ,形成沙漠夏季温度明显高于绿洲 ,进而对绿洲地区增温 ,称沙漠增温效应。石河子地区 1 0 0 km范围内沙漠对绿洲的增温平均 1 .76℃ ( 1～ 2℃ ) ;根据绿洲距沙漠的远近与气温间存在的线性关系 ,回归方程为 :y=2 7.5 2 97- 0 .0 335 x。 r=- 0 .881 3*。沙漠增温效应对绿洲农业有多方面作用 ,形成夏季富照高温、秋季大日较差以及促成棉花在夏季的“冷害”等 ,深刻地影响绿洲特色农业、栽培技术及人们生活     

茄子耐热性遗传表现

 采用4 份耐热性不同的茄子亲本半轮配法配制4 ×4 双列杂交, 对P₁ 、P₂ 、F₁ 、F₂ 、BC₁ 等5 个世代四叶期幼苗在温室内进行高温(平均昼/ 夜温度38. 8/ 24. 2 ℃) 处理, 同期田间栽培(平均昼/ 夜温度34. 4/ 22. 6 ℃) 。采用Hayman’s 法分析苗期耐热指数和成株期坐果率的调查数据, 表明, 茄子耐热性为不完全显性遗传, 受两对以上基因控制, 符合加性—显性模型, 其中加性效应占更主要成分。据此提出了耐热性选择方法。     

Effects of temperature on ascospore germination and penetration of oilseed rape (Brassica napus) leaves by A- or B-group Leptosphaeria maculans (phoma stem canker)

Ascospores of both A-group and B-group Leptosphaeria maculans germinated at temperatures from 5 to 20°C on leaves of oilseed rape. Germination of ascospores of both groups started 2 h after inoculation and percentage germination reached its maximum about 14 h after inoculation at all temperatures. Both the percentage of A-/B-group ascospores that had germinated after 24 h incubation and germ tube length increased with increasing temperature from 5 to 20°C. Germ tubes from B-group ascospores were longer than those from A-group ascospores at all temperatures, with the greatest difference at 20°C. Hyphae from ascospores of both groups penetrated the leaves predominantly through stomata, at temperatures from 5 to 20°C. A-group ascospores produced highly branched hyphae that grew tortuously, whereas B-group ascospores produced long, straight hyphae. The percentage of germinated ascospores that penetrated stomata increased with increasing temperature from 5 to 20°C and was greater for A-group than for B-group L. maculans after 40 h incubation.     

Leaf, floret and seed infection of wheat by Pyrenophora semeniperda

Infection processes of Pyrenophora semeniperda on seedling and adult wheat leaves and wheat ears were investigated. Almost 100% germination of conidia occurred on seedling leaves, compared with 20–30% on adult leaves. Appressoria formed over the anticlinal epidermal cell walls and haloes always accompanied infection. Sometimes papillae formed within the leaves as a resistance mechanism. Infection hyphae ramified through the intercellular spaces of the mesophyll resulting in cellular disruption. The infection processes on floral tissues were similar to those observed on leaves; however, no infection occurred on anther, stigmatic or stylar tissues. Infection of ovarian tissue occurred both with and without appressoria formation. Hyphae grew mainly in the epidermal layers and appeared unable to breach the integumental layer as no growth was observed in endosperm or embryo tissues. The optimum dew period temperature for conidial germination was 23·6°C, compared with 19·9°C for lesion development, 20·4°C for the production of infection structures on seedling leaves and 23·7°C for floret infection. Leaf disease development occurred in a logistic manner in response to dew period, with maximum infection observed after 21 h compared with > 48 h in seeds. An initial dark phase during the dew period was necessary for infection and temperature after the dew period had an effect, with significantly more numerous and larger lesions being formed at 15°C compared with 30°C. Seedling leaves were found to be more susceptible than older leaves, under both field and controlled environment conditions. Infection of wheat seeds following inoculation of ears, or after harvest burial of inoculated disease-free seeds, was demonstrated. In the latter, 3-week-old seedlings were slightly stunted, whereas older plants were unaffected. The apparent unimportance of this plant pathogen as a cause of leaf disease in relation to its poor adaptation to dew periods and dew period temperature is discussed, along with the importance of its seed borne characteristics.     

节能日光温室中番茄灰霉病发生规律的研究

通过 3年对节能日光温室环境温湿度监测、病菌孢子捕捉和番茄灰霉病发生规律研究明确 ,一般年份 ,灰霉病在番茄叶片上表现为明显的始发期、盛发期和末发期等 3个阶段 ;果实发病后 ,即进入盛发期。温室中病菌的发生与病害呈正相关 ,病菌的高峰期较病害的高峰期提前10～15d。持续的低温、高湿、苗期带病等是引起番茄灰霉病发生的重要因子。提出要从优化设施环境等方面来控制番茄灰霉病的危害。     

温湿度调控对番茄灰霉病菌产生的细胞壁降解酶的影响

 番茄灰霉病菌在致病过程中能够产生4种细胞壁降解酶,以PMG酶活性最高,其次是β-葡萄糖苷酶和PG酶,Cx最少。灰霉病菌在不同温度下侵染番茄叶片时产生的致病酶活性不同,4种酶在20℃时表现了最高的活性,15℃次之,当温度达到25℃时,各种酶的活性都急剧下降,随着温度的再升高,酶活更低。随着湿度的增高,病菌产生的细胞壁降解酶的活性也增加,当相对湿度达到90%以上时,4种酶的活性也达到最高。温湿度对番茄灰霉病菌产生细胞壁降解酶的影响趋势,与其对发病的影响趋势是一致的。     

低温胁迫下弓葵幼苗膜脂过氧化及保护酶活性的变化

 低温胁迫下弓葵( Butia capitata Becc) 幼苗叶片的MDA 含量逐渐增加, 膜脂过氧化作用增强。- 8 ℃条件下的膜脂过氧化作用明显强于2 ℃。细胞膜透性在2 ℃条件下变化不大, - 8 ℃时则随低温胁迫时间延长而急剧上升, 细胞膜受到伤害。- 8 ℃胁迫下细胞保护酶SOD、POD 和CAT 活性短期(6 h) 内升高,然后下降, 24 h 以后3 种保护酶受到低温胁迫的严重抑制。在2 ℃胁迫下, SOD 活性在6 h 内变化不大, 随后下降; CAT活性变化趋势与- 8 ℃时相似, 但变化幅度较小; POD 虽也呈现先升后降的趋势, 但降幅明显小于升幅, 至48 h 时POD 活性仍维持较高水平。2 ℃低温胁迫不是抑制而是促进POD 活性的提高。