Low leaf to fruit ratio delays fruit maturity of ‘Lapins’ sweet cherry on Gisela 5

Canopy leaf to fruit ratio (L:F) of 6-year-old ‘Lapins’ sweet cherry trees on Gisela 5 rootstock was manipulated at the end of stage II (38 DAFB) of fruit development. While control trees showed a L:F ratio of 0.7:1 without alteration, on other trees young fruit were manually removed to yield L:F ratios of 2:1 and 3:1, respectively. All leaves and young fruit on trees were counted 30 DAFB. The effect of altering the source–sink ratio of whole trees on sweet cherry fruit quality parameters (fruit increment, fruit mass, color, total soluble solids content, contents of individual sugars and organic acids) was evaluated in the study. High leaf area to fruit (LA:F) ratios influenced significantly darkest fruit color, higher fruit mass, higher total soluble solids content and higher ratio between sugars and acids, which corresponded to better ripening stage. Contents of glucose, fructose and sorbitol, but not sucrose, sum of individual sugars, and the content of malic acid differed significantly among fruit of the different treatments. Fruit of the most advanced maturity stage (treatment 3:1) had the highest quality. Each day of improved L:F ratio counts towards better sweet cherry fruit quality. The results show that low L:F ratio influenced prolonged ripening process and delayed fruit maturity of ‘Lapins’ sweet cherry.     

枇杷幼果冻害低温等级指标的确定

根据福建省近5a枇杷幼果低温箱试验和低温过程山坡地枇杷冻害观测试验结果,以及主产省福建、浙江历史灾情资料,采用归纳分析和对比印证等方法,对枇杷幼果冻害的低温等级指标进行研究。结果表明：枇杷幼果冻害低温等级指标可用日最低气温（Tmin）和低温持续天数（DD）表示,各级冻害指标分别为,轻度：-2.5℃＜Tmin≤-1.0℃,DD≤3d;中度：-3.5℃＜Tmin≤-2.5℃,DD≤3d或-2.5℃＜Tmin≤-1.0℃,DD＞3d;重度：-4.5℃＜Tmin≤-3.5℃,DD≤3d或-3.5℃＜Tmin≤-2.5℃,DD＞3d;极重：Tmin≤-4.5℃,DD≤3d或Tmin≤-3.5℃,DD＞3d。历史灾情资料验证结果表明,冻害等级指标在福建莆田的推算准确率为61%,在浙江临海、黄岩为87.5%,说明枇杷幼果低温冻害等级指标可应用于低温冻害预测。     

幼龄枸杞园套种模式及其经济效益分析

在水资源日趋紧张的扬黄灌区,采用枸杞套种红葱的种植模式,能有效地提高土地利用率,增加单位面积产量、产值,提高经济效益和单方水的效益,是解决枸杞栽植初期种植产量低、土地利用率低、经济效益低的“三低”问题的主要栽培模式。     

镰刀菌粗毒素的特性及对小麦幼胚愈伤组织生长的影响

对镰刀菌粗毒素特性的研究表明,粗毒素能强烈抑制植物种子发芽,并随毒素处理浓度的增大,时间的增长而增强;毒素具有一定的热稳定性,对小麦幼胚愈伤组织有强烈的杀伤力。     

石楠盘粉虱生物学特性研究

石楠盘粉虱目前仅发现为害石楠,以蛹越冬。一年三代,在平均室温（18. 67± 3. 65）℃下,其世代历期平均为 64.9天。本文对各虫态的形态特征及习性作了描述。天敌主要有细蜂 1种。     

Dietary strategies to improve the iron and zinc nutriture of young women following a vegetarian diet

Dietary strategies to enhance the content and bioavailability of iron and zinc in vegetarian diets were compiled. Strategies included increasing promoters and decreasing antagonists of iron and zinc absorption, adopting food preparation and processing methods which hydrolyze the phytate content of cereals and legumes, and using iron cookware. These strategies were used to devise two vegetarian menus based on food consumption patterns derived from three day weighed food records of 78 Canadian lacto-ovo-vegetarian adolescents. The iron and zinc, as well as calcium, phosphorus, thiamin, riboflavin, niacin, vitamin A, protein and energy content of the devised menus were all higher than the actual intakes and the corresponding Canadian recommended nutrient intakes. Results show the overall nutrient adequacy of the recommended vegetarian menus and indicate that young lacto-vegetarian women can potentially meet their estimated dietary requirements for absorbed iron and zinc through modest modifications to the diet. Laboratory studies designed to measure the total amount of iron and zinc absorbed from these diets by young vegetarian women are needed to verify the efficacy of the devised menus.     

小麦不同外植体离体培养及转化效率的比较研究

小麦基因枪法遗传转化中幼胚组织培养有很强的基因型依赖性．这在很大程度上限制了转基因小麦的广泛应用。为了建立克服基因型障碍的小麦高效再生系统．促进转基因小麦的规模化应用，对15个小麦基因型的幼穗、幼胚两种外植体的愈伤组织诱导率、绿苗分化率进行了比较研究。结果表明，各基因型愈伤组织诱导率在两种外植体之间无差异，但幼穗外植体产生的愈伤组织质量好于幼胚。15个基因型幼穗外植体的绿苗分化率均高于其相应的幼胚外植体绿苗分化率，表明幼穗是很好的外植体材料。对其中H6756和H311两个基因型不同外植体所形成的愈伤组织进行了基因枪转化，姑果表明，幼穗受体的基因转化效率明显高于其相应幼胚受体的基因转化效率。     

孜然套种糯玉米间毛豆高效栽培技术

孜然芹．糯玉米．毛豆三种作物在一个生产年度内在同一田块上种植,能显著提高光合产量,土地利用率和经济效益。本文主要对孜然套糯玉米再间作毛豆的栽培技术和生产环节进行了详细阐述,并提出了一些高效的耕作和管理思想,以期为生产户服务。     

基因型和采样时期对甜樱桃体细胞胚胎发生的影响

以不同基因型甜樱桃的未成熟胚为材料,从幼胚的采样时期、蔗糖浓度和2,4-D等方面探讨了甜樱桃体细胞胚胎发生的影响因素。结果表明：采样时期在花后35 d左右,幼胚≤5 mm时,胚性愈伤组织形成的频率较高（92.9%）;体细胞胚胎发生的适宜培养基为MS＋2,4-D 2.0 mg/L＋蔗糖40 g/L。     

水稻同核异质体幼穗分化过程中同工酶的变化分析

[目的]探索水稻幼穗分化过程中同工酶的变化与胞质雄性不育的关系。[方法]以冈型胞质雄性不育系G46A及其保持系G46B为材料,分别取处于第一苞分化期、一次枝梗原基分化期、二次枝梗原基分化期、颖花原基分化期、雌雄蕊分化期、花粉母细胞形成期、减数分裂期、单核期、双核期、三核期的叶片及处于花粉母细胞形成期、减数分裂期、单核期、双核期、三核期的幼穗进行酯酶同工酶(EST)、细胞色素氧化酶同工酶(COD)、过氧化物酶同工酶(POD)电泳分析。[结果]在叶片中,不育系与保持系相比,COD、POD酶谱除在染色深度上存在差异外,在谱带数目及分布未见差异;EST酶带的分布及数目从花粉母细胞形成期开始出现差异,并持续到三核期,且不育系酶带数目及活性要低于保持系。在幼穗中,不育系与保持系相比,EST酶谱带分布在花粉母细胞形成期出现差异,单核期更加明显,COD、POD酶谱带分布、强度、数目差异均从单核期呈现;不育系中3种同工酶带数目均低于保持系,且随着发育时期的深入表现的更明显。这与细胞学观察G46A单核期孢子体败育的结果相吻合。[结论]可以将细胞色素氧化酶同工酶及过氧化物酶同工酶特征酶带的缺失作为胞质雄性不育系败育的生理生化指标。