农田沙漠化演变中土壤质量的生物学特性变化   总被引：9，自引：5，他引：9  

苏永中  赵哈林  张铜会  文海燕 《干旱区研究》2002,19(4):64-68

通过研究处于沙漠化过程中的科尔沁沙地旱作农田土壤酶活性与基础土壤呼吸活性，分析了土壤质量生物学特性的沙漠化演变。结果表明，土壤酶活性与基础土壤呼吸对沙漠过程中环境的变化反应敏感，随着沙漠化程度增加，与土壤物理化学肥力因素有关的过氧化氢酶、脲酶和碱性磷酸酶的活性和土壤呼吸活性随之下降。土壤酶活性和呼吸活性与土壤有机质和养分有极显著的相关，在一定程度上可以用酶活性和呼吸强度表征有机质和养分的状况及其数量的变异，因此，可以作为农田沙漠化演变中土壤质量特征变化的重要辅助指标。  相似文献   

早熟、优质、耐贮梨新品种新梨7号选育研究   总被引：7，自引：0，他引：7  

刘建萍  阎春雨  程奇  王新建  吴翠云 《果树学报》2002,19(1):36-38

以库尔勒香梨为母本,早酥梨为父本,有性杂交选育成新梨７号品种。该品种同时兼备优质、早熟与耐贮藏性;该品种遗传了父本的早熟性,比父本更早熟１５~２０ｄ,盛花期~果实可食期约８０~９５ｄ,属于早熟品种;且遗传了母本品质性状的质地酥脆、耐贮、清香、阳面红晕,比母本果个大,果心小。果柄木质化,丰产抗风。新梨７号果实贮藏期的可溶性固形物、果实重量、果实硬度和果实前期腐烂率的变化与库尔勒香梨基本相似,但耐热能力高于母本。凡适宜香梨、早酥、苹果梨和巴梨种植的地区,都适宜该品种的种植。  相似文献   

大果型鲜食枣新品种‘大白铃’   总被引：1，自引：0，他引：1  

高丽  郭裕新  周广芳  单公华  王斌 《园艺学报》2002,29(1):85-85

 ‘大白铃’为大果型鲜食枣优良新品种。果实特大, 平均单果质量24. 5 ~ 25. 9 g, 最大80 g,整齐, 外形美观, 品质优良。早实, 丰产, 抗逆性强。  相似文献   

早熟优质长豇豆新品种‘鄂豇豆2 号’   总被引：1，自引：0，他引：1  

陈禅友  周余泉  赵新春  胡志辉  张凤银 《园艺学报》2002,29(1):88-88

 ‘鄂豇豆2号’是经有性杂交选育而成的早熟蔓生豇豆新品种。该品种荚浅绿色, 长60 cm,单荚质量18~ 24 g。早熟, 荚商品性状优良, 产量高, 对光周期反应不敏感, 田间疫病、煤霉病、病毒病发病率低, 适宜于春、夏、秋各季栽培, 已在全国大部分省份推广种植成功。  相似文献   

Variation of Parthenium hysterophorus in response to soil quality: implications for invasiveness   总被引：1，自引：0，他引：1  

C Annapurna  & J S Singh 《Weed Research》2003,43(3):190-198

Summary The performance of Parthenium hysterophorus , native to the tropical Americas and invasive to several countries, was evaluated for response to soil quality. Phenological (six stages) and quantitative growth variables [relative growth rates in height (R_h) and diameter (R_d)] were measured every fortnight. Based on harvest data, the variables, root:shoot (R:S) ratio, specific leaf area (SLA), relative growth rate in biomass (R_w), net assimilation rate (NAR) and dry matter allocation to plant components, were determined. High clay content in soils prolonged the rosette stage, enhanced R_h and R_d and hampered root growth, but promoted biomass allocation to shoots. The extreme degree of plant mortality was observed, with only 33.3% individuals surviving to reproduce in the soils with highest clay contents. This appears to be one of the most important findings that certainly has a major bearing on the range of adaptation of the weed. Seed mass declined whereas seed production increased in relatively coarser soils with the exception of nearly pure sand. In soils rich in clay, plants produced a smaller number of larger seeds. These data suggest that variation in fundamental functional traits would enable P. hysterophorus to adjust to a variety of habitat conditions.  相似文献   

分蘖洋葱的特性及高效栽培技术研究     

相元萍 《长江蔬菜》2003,(4):37-38

分蘖洋葱最突出的特性是分蘖性强，生长快，分蘖的多少直接影响分蘖洋葱的产量。试验表明：12-20℃条件最适宜其生长，良好的土壤营养和适宜的环境有利于分蘖洋葱的分蘖生长，获得高产、优质商品。  相似文献   

广东优质籼稻抗稻瘟病育种研究进展   总被引：5，自引：0，他引：5       下载免费PDF全文

朱小源  杨祁云  伍尚忠 《植物保护学报》2003,30(2):209-216

通过对广东优质籼稻品种抗瘟性研究、抗病品种的系谱分析以及抗病育种实践的回顾，综述了广东优质稻抗性育种历史及现状，剖析了优质稻抗瘟育种存在的问题及相应对策。提出开发利用不同稻作系统的抗病资源，构建遗传多样性丰富的抗病优质种质，延长品种抗性寿命及解决品种优质与抗病的矛盾。  相似文献   

粉红女士苹果品质特性分析评价   总被引：8，自引：0，他引：8  

鲁玉妙  高华  赵政阳  王雷存  袁景军 《果树学报》2003,20(6):503-505

观察测定了粉红女士苹果成熟采收时和常温贮藏后果实的外观、抗性、果实硬度、总酸、可溶性固形物、维生素C、蒸腾失水率、出汁率、果汁密度以及果汁性状;全面分析评价了该品种的外在、内在、贮藏品质和果汁加工特性。结果表明,粉红女士苹果是一个综合性状优良、耐贮藏的鲜食、果汁加工兼用型苹果新品种。  相似文献   

烯效唑浸种对黄瓜的壮苗效应   总被引：14，自引：0，他引：14  

杨文钰  李青苗  马文波 《中国蔬菜》2003,1(1):6-8

研究不同浓度烯效唑浸种对黄瓜幼苗生长发育的影响。结果表明,烯效唑可抑制黄瓜幼苗徒长,使株高降低,比叶重增加,根冠比和壮苗指数增大,叶绿素含量增加,根系活性增强,在形态上和生理上表现出显著的壮苗效应;烯效唑对黄瓜有极显著的增产作用,以20 mg·kg-1处理最佳,促进增产的主要原因是提高了单株结瓜数。  相似文献   

The egg parasitoids ofThaumetopoea pityocampa in the atlas Mountains near Marrakech (Morocco)     

H. Schmidt  P. Mirchev  G. Tsankov 《Phytoparasitica》1997,25(4):275-281

Studies were performed on 25 egg batches ofThaumetopoea pityocampa (Den. & Schiff.) collected onPinus pinaster Ait. on 29. XI. 1995, in the Atlas Mountains of Morocco near Marrakech at 1400-1800 m above sea level. All the egg masses had been deposited in the autumn of 1995 and were exposed to the parasitoids throughout the developmental period of the host. In 1996, the egg batches, kept singly in test tubes, were observed almost daily. Emerged parasitoids were recorded and separated. The final analyses were made in November 1996 based on the meconia and remains of the emerged or the dead parasitoids in the eggs. In all cases, oviposition occurred from the base to the tip of the needles, distances varying up to 62 mm from the base. The mean number of eggs per batch was 175 (range 34-245), the number of egg-rows varied between 6 and 11, and a 1-cm egg-row contained a mean of 9 eggs. Caterpillars hatched from 72. 7% of the eggs; total mortality of the eggs was thus 27. 3%. The impact of egg parasitoids was 21. 4%. Most of the parasitized eggs were attacked byBaryscapus servadeii (Dom.) followed byOoencyrtus pityocampae (Mercet). Males (1. 5%) were found only in B. servadeii. The emergence rate ofO. pityocampae was much higher in the year of host oviposition than in the following year. B. servadeii emerged in equal numbers before and after hibernation, and in the subsequent year in equal numbers in spring and autumn. The high rate of emergence ofB. servadeii in April-May is discussed in relation to the embryonic development ofThaumetopoea bonjeani (Powel) until the end of winter, as an alternative host ofB. servadeii in the Atlas region.  相似文献