柑橘幼果发育期碳水化合物代谢及其与生长发育的关系

温州蜜柑幼果在盛花后逐渐生长 盛花后6 d开始大量脱落 日本甜夏橙幼果在盛花后12 d内重量未增加，一直处于急剧落果期。甜夏橙幼果中蔗糖含量高出温州蜜柑20多倍，种间还原糖含量变化趋势略有不同。两种柑橘的淀粉含量变化也不同，但它们的淀粉含量与淀粉酶活性、幼果相对脱落率均呈负相关。对幼果碳水化合物代谢与生长、脱落的关系作了讨论。     

Engineering of a Single Chain Variable Fragment Antibody Specific for the Citrus tristeza virus and its Expression in Escherichia coli and Nicotiana tabacum

Citrus tristeza virus (CTV) is one of the most destructive citrus virus diseases in the world. The construction of an engineered antibody, EMBL accession number AJ278109, able to specifically recognize its antigen, i.e. the coat protein of CTV, directly on infected plant material without any purification or manipulation of the entire woody plant. The potential uses of this engineered antibody are discussed.     

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。     

Functional analysis of the 3′ end of avrBs3/pthA genes from two Xanthomonas species

The phytopathogens Xanthomonas oryzae pathovar (pv.) oryzae and Xanthomonas axonopodis pv. citri each contain several avrBs3/pthA family genes. Structural features of these genes important for avirulence and/or virulence functions include a central region of multiple direct repeats and three nuclear localization signals (NLSs) and an acidic activation domain (AAD) at the 3′ end. To identify other regions critical to function in the 3′ ends of these genes, we constructed several chimeras using apl1 and apl2 from X. axonopodis pv. citri and avrXa10 and avrXa7 from X. oryzae pv. oryzae and evaluated their functions by inoculation to citrus and rice. The apl1 and avrXa7 genes are major virulence determinants in citrus and rice, respectively, while the contributions of apl2 and avrXa10 to virulence are negligible or not measurable. Constructs that contained a 417 bp HincII-SphI fragment from the 3′ end of apl1 in combination with the repeats from avrXa7, avrXa10, and apl1 caused a canker phenotype on citrus. Interchange of the HincII-SphI fragment between avrXa7 and avrXa10 abolishes avrXa7 avirulence function and reduces its virulence but it does not affect avrXa10 avirulence function in rice. avrXa7 caused a hypersensitive response (HR) in citrus and replacement of it's 3′ end with that of apl1 resulted in loss of canker and induction of HR. Thus, the HincII-SphI fragment of the avrBs3/pthA gene family is important for avirulence and virulence functions in two different plant species, Oryza sativa and Citrus natsudaidai HAYATA.     

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...     

野生柑橘宜昌橙分布特征及资源评价

宜昌橙（Cirtus caraleriei）是中国特有的野生柑橘资源,为柑橘属中抗寒性最强的原始野生种类,较耐瘠薄和荫蔽,果实供药用,可作柑橘的抗逆砧木和矮化砧木。通过研究国内主要标本馆的馆藏标本和文献资料,分析了宜昌橙的地理分布特征与主要分布区的资源特点。基于402份宜昌橙馆藏标本的分析结果表明: 野生宜昌橙主要分布于我国南方的四川、重庆、湖北、湖南、贵州、广西、云南、陕西、甘肃等9个省区、直辖市,分布区域广、海拔差异较大;不同地区宜昌橙生境和分布数量存在较大差异,陕西和甘肃两个地区采集标本的数量明显少于其他地区,为宜昌橙分布的最北沿;虽然分布点较多,但每个居群的个体数较少,资源储量严重不足。研究结果可为研究宜昌橙的地理分布及资源开发利用、保护等研究提供基础资料。     

QuEChERS-三重四极杆串联质谱测定柑橘中农药基质效应的方法研究

[目的]针对柑橘中常用的农药,采用QuEChERS方法和超高效液相色谱-三重四极杆串联质谱,系统研究了其测定过程中的基质效应.[方法]柑橘样品利用乙酸-乙腈溶液(V︰V=1︰99)提取、GCB净化,采用甲醇-0.1％甲酸水溶液(含1mmol·L-1乙酸铵)作为流动相,正离子多反应监测(MRM)模式,基质外标法定量,可以...