Fruit and seed diversity of domesticated carob (Ceratonia siliqua L.) in Morocco

The carob tree (Ceratonia siliqua L.) is an important economic resource for Morocco's rural populations. This species is used in reforestation actions and its cultivation in modern orchards is being undertaken to valorize marginal lands and substitute for drought sensitive species. However, little data is available on its intra-specific variability and its adaptability. Morphological characters of pods and seeds from 13 ecoregions of private-domesticated carob were used to assess phenotypic variation of this species. These stands extend from south-west to north-east and cover a wide range of Morocco's ecoregions. Pods length, width, thickness, seeds number, pulp weight, seeds yield and seeds length, width, thickness and weight were measured for 390 trees (30 trees per ecoregion). Statistically significant differences were found between ecoregions for all characters which were examined, what indicates a high phenotypic diversity. Principal component analysis (PCA) and hierarchical cluster of all ecoregions lead to identify two major and opposite groups (the northern ecoregions; and the central and south-western ecoregions). Ecoregions of the north of Morocco exhibited the largest and the thickest pods with the highest pulp weight while other ecoregions have relatively short pods but largest proportion of seed yield. Similarly, the northern ecoregions are characterized by the heaviest seeds. A correlation matrix between morphological characters, geographic parameters and precipitation exhibits a positive and a negative correlation of pods thickness and pulp weight with the latitude and the altitude, respectively. Seed yield and weight are negatively and positively correlated to pod width, pod thickness and pulp weight, respectively. In addition, seed weight is positively correlated with the latitude. The geographic pattern of the carob tree and its variability are discussed in this paper.     

早熟高产优质水稻新品种龙粳22的特征特性及栽培要点探讨

[目的]为龙粳22的推广种植提供理论依据。[方法]通过比较龙粳22和对照品种的生长、品质、抗病、抗冷指标,探讨了龙粳22的生产潜力和推广价值。[结果]龙粳22主茎11片叶,生育期130d左右,需≥10℃活动积温2300℃左右;幼苗长势强,秆强抗倒,耐寒;3年区域试验平均产量8.37t/hm2,比对照品种增产4.0%;生产试验平均产量9.53t/hm2,较对照品种平均增产9.0%;米质优良,各项指标均达国家优质米标准。[结论]龙粳22熟期早、产量高、米质优,在黑龙江省第3积温带具有较好的推广应用前景。     

线粒体nad 6基因在油菜种子发育中的特异性表达

以油菜为材料，研究线粒体ｎａｄ６基因在种子发育中的表达。结果表明，ｎａｄ６基因在叶片中的表达很低，在种子发育过程中各阶段均有较高表达，并随种子发育进程而有加强的趋势。推测线粒体ｎａｄ６基因可能除与呼吸作用有关外还有其他功能     

Seed yield and water use efficiency of canola (Brassica napus L.) as affected by high temperature stress and supplemental irrigation

The effects of high temperature stress and supplemental irrigation on seed yield and water use efficiency (WUE) of canola (Brassica napus L.) were studied in a field experiment conducted for 2 years. The experiment was a randomized complete block design arranged in split plot, conducted at Agricultural Research Station of Gonbad, Iran. It was arranged in two conditions, i.e. supplemental irrigation and rainfed. Two cultivars of canola (Hyola401 and RGS003) as subplots were grown at five sowing dates as main plots. The sowing dates were 9 November, 6 December, 5 January, 4 February and 6 March in 2005-2006 and 6 November, 6 December, 5 January, 4 February and 6 March in 2006-2007, to have a wide range of environmental conditions around flowering and seed filling periods, and to coincide reproductive stages of the crop with high temperature stress. Seed yield was improved due to field management practices, such as supplemental irrigation and optimum sowing date. Supplemental irrigation was an efficient practice to mitigate water stress, and to increase aboveground dry matter and seed yield. There was a strongly negative relationship between seed yield and air temperature during reproductive stages. Delay in sowing led to more rapid developmental of canola, decreased aboveground dry matter, leaf area index (LAI), harvest index (HI), WUE, and seed yield. Achieving a high aboveground dry matter was an essential prerequisite for high reproductive growth and a high seed yield. Greater seed yield and WUE at first sowing date were associated with greater LAI and aboveground dry matter, and lower temperatures during reproductive stages. The results support the view that WUE can be used as an indirect selection criterion for seed yield in genotypic selection.     

图书馆为建设社会主义新农村提供支持的有效举措——对“村村大学生”服务方式的思考

“村村大学生”培养计划是黑龙江省开展科教兴农工作的重要举措，是建设社会主义新农村的有力保证。文章论述了高等农业院校图书馆应针对该群体深挖服务潜能，拓展服务方式，全方位配合学校培养优秀的“村村大学生”人才，为地区农村的快速发展提供技术支持和人才保障。     

基于形态学的棉花种子破损检测

以"中棉35"棉花种子为对象,应用图像处理技术,提出了基于形态学的破损识别方法.采用链码算子获取轮廓信息并进行傅里叶算子平滑,根据曲率特征定位轮廓尖端点后,通过轮廓的对称性识别局部破损棉种;基于统计思想,根据大小、形状特征的差异识别严重破损棉种.选取完好、破损棉种各200粒进行识别试验,结果表明破损棉种识别率达到94%.     

脱落酸与种皮对杜梨种子休眠与萌发的影响

以当年新采收杜梨种子和自然贮藏1 a种子为试验材料,研究了种皮和不同浓度的脱落酸(ABA)对诱导杜梨种子休眠与萌发的影响.结果表明:杜梨种皮和脱落酸均能够抑制杜梨种子的萌发,种皮的抑制萌发效应显著大于ABA的作用,杜梨种子去除种皮后,休眠性可被部分解除.脱落酸对杜梨种子抑制萌发的效应在去皮和不去皮种子中表现明显差异,5 mg/L ABA浓度对未去皮种子产生明显抑制效应,20 mg/L ABA浓度对去皮种子产生明显抑制效应,说明未去皮种子对ABA的敏感性大于去皮种子.种皮与ABA的双重抑制效应,使种子对ABA浓度水平差异的敏感性增强.不同激素组合试验说明了GA3、6-BA和ABA在杜梨种子休眠与萌发中的作用.     

Wheat Seed Presoaking for Improved Germination

Seed presoaking improves wheat germination under marginal moisture conditions. The duration of seed presoaking was studied at The University of Arid Agriculture, Rawalpindi, using 10 wheat varieties. Seed presoaking beyond 12 h does not improve germination further, and beyond 21 h, germination rate is drastically reduced.     

春播和秋播对南方春大豆种子活力的影响

试验采用春播（４月４日）和秋播（７月３０日）两种播期法，研究春播种子活力低，秋播种子活力高的生理生化原因，结果表明，种子发芽率，发芽指数，电导率，过氧化物酶活性和真菌侵染率，这些反映种子活力的生理指标，秋播种子均优于春播种子，此外，秋播种了表皮结构较春播种子致密，种子表面小孔数目少而小，这可能也是秋播种子活力高的原因之一。     

浅谈早稻生产的几个问题

要夺取早稻生产的持续增产,扩大早稻种植面积,选择适宜品种,选准栽培方式,培育健壮秧苗,建立高产群体是五项关键措施。