应用均匀设计法筛选稗草病原菌产孢最佳配方培养基

 筛选生防菌最佳产孢培养基是高效、大量生产生防菌孢子的基础。应用均匀设计法结合二次多项式回归分析,从众多因素中筛选出稗草病原菌弯孢菌(Curvularia lunata)和互格交链孢菌(Alternaria alternata)最佳产孢培养基组分,建立多元二次回归数学模型。弯孢菌最佳产孢组分为胡萝卜、芹菜、欧芹、水芹、莴苣、蔗糖和Vc;互格交链孢菌最佳产孢组分为胡萝卜、芹菜、水芹、莴苣和蔗糖。根据回归模型计算理论(拟和)产孢值。比较实测产孢量和理论产孢值,结果表明,稗草病原菌的实测产孢量和回归模型拟合产孢值非常接近,拟合误差小。说明采用均匀设计法从众多因素中筛选培养基最佳成分是可行的。     

Does sand content in spawning substrate result in early larval emergence? Evidence from a lithophilic cyprinid fish

The spawning success of lithophilic salmonids is strongly influenced by the fine sediment content (“fines”) of spawning substrates, yet knowledge on the impacts of fines on the spawning of non‐salmonid lithophiles remains limited, despite their ecological and socio‐economic importance in European rivers. Consequently, the aim here was to use an ex‐situ experiment to investigate the impact of sand content on egg survival and timing of larval emergence of the surface‐spawning cyprinid European barbel Barbus barbus. Thirty incubator boxes within a recirculating system were filled with one of five experimental sediment mixtures (0%–40% sand by mass) that each contained 300 fertilised eggs at a depth of 50 mm. Emerged, free‐swimming larvae were captured and counted daily to assess grain‐size effects on larval survival and emergence. Specifically, total proportion of emerged larvae, cumulative daily proportion of emerged larvae and time required to reach 50% emergence were measured during the study. Whilst the proportion of sand in the sediments did not have a significant impact on egg‐to‐emergence survival (mean survival per treatment 75%–79%), it significantly affected the timing of larval emergence to the water column; early emergence was detected in treatments with elevated sand content (on average, 50% emergence after 12–13 days versus 19 days in the control). Similar to findings from salmonid studies, these results suggest high sand content in spawning gravels can influence timing of larval emergence and potentially cyprinid lithophilic fish survival.     

杂交稻强优恢复系南恢125的选育与应用

在利用国内外优良恢复系作亲本杂交育成中间材料N175基础上,再聚合杂交,培育成功强优恢复系南恢125。该恢复系具有株叶形态优良、恢复力强、恢复谱广、配合力好、花粉量多、制种产量高、较抗稻瘟、米质优等特点。用南恢125配组的Ⅱ优125、泸优125、特优125等组合在各级区试中表现突出,其中Ⅱ优125于2006年通过福建省农作物品种审定委员会审定,显示出良好的生产应用前景。     

水稻淀粉合成代谢相关基因与千粒重QTLs的连锁分析

稻米淀粉的合成和积累是水稻千粒重形成的重要基础之一。在水稻千粒重QTLs定位分析基础上，对本研究克隆的14个水稻胚乳淀粉合成与积累相关基因及已报道的和预测的42个相关基因进行了电子定位分析，比较水稻淀粉合成代谢相关基因与千粒重QTLs的连锁关系。发现有38个基因位点与千粒重QTLs连锁，说明千粒重形成与胚乳淀粉积累与淀粉结构形成代谢密切相关。本研究结果将为进一步研究水稻产量形成的分子机理提供参考。     

两系不育系P88S育性转换的积温模型构建(英文)

[目的]构建两系不育系水稻P88S育性转换的积温模型。[方法]对2005年和2006年P88S在海南育性转换的试验数据进行分析。[结果]发现P88S在气温在26～28℃之间的可育性是由温度的绝对值和温度的累积效应决定的,并得到了1个基于双稳态的温度累积效应模型。[结论]利用积温模型可以有效地说明两系不育系春秋季育性转换温度的不对称性,即从可育转换为不育需要更高的温度,从不育转换为可育则需要更低的温度,并说明影响水稻育性的因素可能存在累加效应。     

The resistance of meat chickens vaccinated by aerosol with a live V4 Newcastle disease virus vaccine in the field to challenge with a velogenic Newcastle disease virus

Meat chickens housed on a commercial broiler farm in Australia were vaccinated once at 10 to 11 days-of-age by aerosol with live V4 Newcastle disease virus (NDV) vaccine. Groups of vaccinated and unvaccinated birds were flown to Malaysia, where they were challenged with a virulent strain of NDV. Survival rates in vaccinated chickens challenged 7, 14, 21 or 31 d after vaccination were 0.47, 0.77, 0.97 and 0.92, respectively. All unvaccinated chickens died due to Newcastle disease (ND) following challenge. Chickens in Australia and Malaysia were bled and the serums tested for haemagglutination-inhibiting (HI) antibody to NDV. Many vaccinated birds with no detectable antibody, and all birds with a log2 titre of 2 or greater, survived challenge. The results showed that this V4 vaccine induced protective immunity in a significant proportion of chickens within 7 d of mass aerosol vaccination. This early immunity occurred in the absence of detectable circulating HI antibody. Non-HI antibody mediated immunity continued to provide protection up to 31 d after vaccination. Almost all vaccinated birds were protected within 3 w of vaccination. It is concluded that the V4 vaccine is efficacious and could be useful during an outbreak of virulent ND in Australia.     

日本晴与5个优良恢复系的多态性标记筛选及遗传差异分析

遗传基因的分离需要供、受体亲本间较大的遗传差异.该文利用均匀分布于水稻12条染色体的429个SSR标记,分析了日本晴与5个自育优良恢复系之间的多态性标记及分布密度,进而评价它们间的遗传差异性.结果显示,日本晴与西恢18号、缙恢35、R225、R232和R250之间的多态性标记数分别为263,253,253,255和240个;多态率分别为61.31%,58.97%,58.97%,59.44%和55.94%;每个标记间的平均物理距离分别为1.59,1.61,1.62,1.62和1.72 Mb.每个SSR位点可检测到的等位基因数目为2~5个,平均每对SSR引物检测到2.35个等位基因.各亲本之间的遗传距离在0.121 7~0.896 7之间,日本晴与5个恢复系间的平均遗传距离为0.857 6.聚类分析也将日本晴与5个恢复系分为两大亚类,表明它们之间存在极大的遗传差异.这些材料和结果对水稻遗传基因的分离具有重要意义.     

杂交早稻K优619高产制种技术

K优619系温州市农科院选育的籼粳型早杂新组合，制种易获高产，1998～1999年在遂昌县制种9.98 hm2，平均单产3.05 t/hm2，其中1.6 hm2连片制种单产达4.32 t/hm2。对其高产制种技术进行了总结。     

不同秧龄移栽对恢复系播始历期的影响

在制种实践中,恢复系402,298, 191的播始历期随秧龄的延长而延长.试验结果进一步表明,3～6叶期移栽,播始历期无明显变化;从7叶期开始,每推迟1叶移栽,播始历期延长2～3 d;当恢复系402,298移栽叶龄增至9叶,191增至10叶时,播始历期大幅缩短,且出现早穗.因此,在制种中父本移栽叶龄与父母本花期相遇的关系值得重视.