Genetic analyses of resistance of the wheat differential cultivars Carstens V and Spaldings Prolific to two races of Puccinia striiformis

Genetic analysis of resistance of wheat seedlings to two races of Puccinia striiformis was conducted on F₁, F₂ and F₃ generations from crosses Carstens V (CV) × Lee, Spaldings Prolific (SPA) × Lee and CV × SPA. F₂ generations from crosses of CV and SPA with Strubes Dickkopf (SD) were also studied. The plants were classified into six resistance classes and analysed by factorial correspondence analysis and nonhierarchical classification. The two P. striiformis isolates tested were a French isolate of race 43E138 and a Lebanese isolate of race 2E16, selected for the differences in their virulence spectra for the common differential cultivars Strubes Dickkopf and Nord Desprez. Resistance of CV and SPA was recessive and dominant to races 43E138 and 2E16, respectively. CV possessed three or four resistance genes, one of them being expressed with both races. Two genes of CV had a cumulative effect for resistance to 43E138 and two or three gave dominant resistance to 2E16. SPA had three resistance genes, all of which gave resistance to 2E16 and two of which also gave resistance to 43E138. SPA had one gene in common with CV for resistance to both races. Furthermore, the gene for resistance to race 2E16 in CV and SPA was allelic with a gene in SD, and was probably Yr25 .     

甜橙新品种‘兴国甜橙3-5’

 ‘兴国甜橙3-5 ’是从实生‘兴国甜橙’后代中选出的新品种。果皮橙黄至橙红色。果实近圆球形, 平均单果质量167. 7 g , 可溶性固形物含量13. 6% ~ 15. 1%, 总糖含量10. 3% ~ 11. 5%, 总酸含量0. 47%~ 0. 93%, 可食率79. 27%~ 80. 75%, 果汁率65. 18%~ 65. 96%, 11 月上旬成熟。     

日粮中添加柑桔皮粉对产蛋后期蛋鸡钙磷代谢的影响

将 48周龄黄金褐蛋鸡 10只随机分成两组 ,对照组喂基础日粮 ,试验组用 2 5 %的柑桔皮粉等量替代基础日粮中的玉米 ,结果表明 :试验组钙磷表观代谢率为 65 79%、46 3 9% ,钙比对照组 (62 3 0 % )提高了 3 49个百分点 (P <0 0 5 ) ,磷比对照组 (4 7 5 2 % )降低了 1 13个百分点 (P >0 0 5 )。     

Growth- and leaf-temperature effects on photosynthesis of sweet orange seedlings infected with Xylella fastidiosa

The effects of growth and leaf temperature on photosynthesis were evaluated in sweet orange seedlings ( Citrus sinensis cv. Pera) infected with Xylella fastidiosa (the bacterium that causes citrus variegated chlorosis, CVC). Measurements of leaf gas exchange and chlorophyll  a fluorescence were taken at leaf temperatures of 25, 30, 35 and 40°C in healthy and infected (without visible symptoms) seedlings submitted to two temperature regimes (25/20 or 35/20°C, day/night), not simultaneously. The CO₂ assimilation rates ( A ) and stomatal conductance ( g _s) were higher in healthy plants in both temperature regimes. Values for A and g _s of infected and healthy plants were higher in the 35/20°C regime, decreasing with leaf temperature increase. In addition, differences between healthy and infected plants were higher at 35/20°C, while no differences in chlorophyll  a fluorescence parameters were observed except for potential quantum efficiency of photosystem II, which was higher in infected plants. Low A values in infected plants were caused by low g _s and probably by biochemical damage to photosynthesis. The high alternative electron sink of infected plants was another effect of reduced A . Both high growth and high leaf temperatures increased differences in A between healthy and infected plants. Therefore this feature may be partially responsible for lower growth and/or productivity of CVC-affected plants in regions with high air temperature.     

基于SRAP分子标记的11份柑橘种质材料遗传多样性分析

为分析11份柑橘种质材料的遗传多样性,本研究以7份沙糖橘种质以及4份其他柑橘种质为试验材料,利用SRAP分子标记进行分析,并用UPGMA法进行聚类.结果表明:160对引物组合筛选出20对引物组合扩增条带清晰,11份种质材料两两之间遗传相似系数在0.322 1～0.931 6之间.沙糖橘和金葵蜜橘间的遗传相似系数最大,为...     

中日水稻品种的食味比较

近年来日本稻米品质和食味研究取得了举世瞩目的成就。在中国,由于经济快速发展,稻米食味研究逐渐展开,为了给中国优质食味品种选育提供理论依据,从1998年开始对中日品种进行食味比较研究,以食味理化特性及品尝鉴定试验研究结果为依据,分析了中国水稻品种食味特性,即低直链淀粉含量和低蛋白质含量兼备的品种很少,结果导致食味品尝试验各项目的平衡性不好,综合评价不如日本优良食味品种。     

南宁市冬种番茄引进品种比较试验

对9个番茄新品种的比较试验结果表明：综合性状最好的品种是万利达,其次是美国63和英雄2号。这三个品种表现为产量高、耐寒、抗病性强,果实美观坚硬、耐贮运,商品性好,具有很强的市场竞争力,适合在南宁地区推广种植。     

烤烟品种中川208和湘烟7号在攀枝花烟区的适应性研究初报

以云烟87为对照,通过中川208、湘烟7号在攀枝花烟区的适应性比较试验表明：1.中川208、湘烟7号品种较云烟87还苗快,长势强,生长迅速,下部叶发育充分,整体表现较好。2.中川208、湘烟7号的农艺性状、经济性状、抗病性表现总体优于云烟87,单湘烟7号品种需要在生产中进一步研究栽培技术措施以提升烟叶化学品质。3.中川208、湘烟7号可适当扩大试种面积,进一步深入研究其在攀枝花烟区的生态适应性。     

海南优质稻米的品质研究[①]

随着现代人们生活水平的提高,稻米消费的需求也正在发生改变。三亚市南繁科学技术研究院连续承办两届“海南好米”活动,从海南征集稻米品种,活动涵盖了海南省推广的绝大部分优质稻米。本实验通过检测“海南好米”评选活动中得分较高的水稻品种米质,并与在全国优质稻米品质评选活动中获奖的水稻品种米质进行比较,分析了海南地区优质水稻品种米质的特点及未来可能的改良方向。结果表明：海南省籼稻米粒型以长型为主,大小形状较为理想。但外观品质较差,主要表现在稻米的垩白粒率、垩白度和裂纹率偏大。胶稠度大多为中软胶稠度,碱消值多数处于中高级。中、低直链淀粉含量品种居多,蒸煮品质总体较理想。今后海南籼稻品质改良目标应该放在减小垩白粒率、垩白度和裂纹率的等外观品质上,从而提高海南地区优质水稻的商品价值。     

不同烤烟品种烟叶质量对比分析研究

采用田间随机区组试验设计方法结合数学统计分析方法,研究“云烟97”、“云烟121”、“秦烟96”、“NC71”4个烤烟品种烟叶产质量。结果表明：云烟121烟株农艺性状、烟叶外观质量、烟叶化学成分含量最好;4个烤烟品种各等级烟叶总氮含量偏低,总糖、还原糖含量均偏高,烟碱、氯、钾均在优质烟叶适宜范围。