水杨酸诱导对苹果体内防御酶活性的影响

为研究叶面喷施水杨酸(SA)对不同苹果品种防御酶活性的影响,以抗病品种‘北之幸’和感病品种‘礼泉短富’为试验材料,对不同浓度水杨酸处理前后的苹果叶片进行防御酶活性测定。结果表明,经水杨酸处理后,‘北之幸’和‘礼泉短富’的β-1,3-葡聚糖酶、POD、PAL和PPO活性均有提高,且高于对照植株。其中‘北之幸’的β-1,3-葡聚糖酶、POD、PAL和PPO活性分别是对照的2.04倍,6.19倍,2.73倍和2.32倍;‘礼泉短富’的β-1,3-葡聚糖酶和PAL活性分别是对照的1.82倍和1.70倍,POD活性是对照的5.68倍,PPO活性是对照的4.00倍。由此可见,水杨酸处理可以不同程度的提高植株体内抗性相关酶的活性,但不同品种间存在差异。     

不同苦荞品种花和籽粒空间分布特征及差异分析

以8个苦荞品种为试验材料,研究不同苦荞品种花和籽粒在植株不同部位的分布特征及差异。结果表明,不同苦荞品种花和籽粒总数存在显著差异,其中川荞2号总花数、总籽粒数最高,分别为3 046.6和1 367.8,而川荞1号最少,分别为1 017.6和487.2,品种间总花数和总籽粒数变异系数分别为34.8%、29.0%。不同苦荞品种花和籽粒空间分布呈现相同趋势,均主要分布于分枝上,分别占整株的76.3%和74.2%以上,且均显著高于主茎,分别高68.7%~87.0%和65.2%~84.5%。生产上可通过调控分枝的有效籽粒数来提高苦荞产量。     

利用MAS技术改良香稻‘R15’的直链淀粉含量

R15是适应性较广,产量较高的中熟晚籼香稻品系,但由于含有Wx^a基因,其直链淀粉含量高达23.5%,严重影响食用口感。因此,我们以含有Wx^b等位基因的不育系Y58S为供体,通过杂交、回交,利用RAD测序技术、分子标记辅助筛选等技术,经过8个世代的筛选,成功用Wx^b基因替换掉R15中的Wx^a基因,培育出1个新的纯合株系——‘深华R16’,其染色体上有10882234 bp长度的碱基,基因型和供体亲本‘Y58S’一致,占2.92%;有362363285 bp长度的DNA片段基因型和受体亲本‘R15’一致,占97.08%;其直链淀粉含量为14%。将‘Y58S’分别与‘深华R16’和‘R15’进行组配,结果表明,‘Y58S’/‘深华R16’组合的直链淀粉含量(13.9%)低于‘Y58S’/‘R15’组合的直链淀粉含量(19.9%),其它米质性状与农艺性状基本一致。本研究为分子标记辅助育种提供了新思路,培育出一新的水稻品系。     

禾谷镰孢菌FGSG＿09482基因功能初探

为研究禾谷镰孢菌FGSG09482基因的生物学功能,以禾谷镰孢菌为试材,采用Split-Marker基因敲除技术构建基因敲除盒,PEG (聚乙二醇)介导转化法转化禾谷镰孢菌原生质体,在含有潮霉素的培养基上培养筛选,获得FGSG09482基因敲除突变株。通过观察比较其敲除突变体表型,从而分析鉴定该基因的生物学功能。结果表明:以野生型PH-1作为对照,敲除突变体的菌落形态没有明显变化,分生孢子形态没有明显差异,培养滤液颜色没有明显区别。分生孢子侵染番茄果实实验表明,以番茄果实为侵染宿主,对比野生型PH-1,突变体致病力没有减弱。但突变体菌落的生长速率滞后于野生型PH-1;敲除突变体的产孢量低于野生型PH-1;有性杂交实验表明,敲除突变体几乎不产生子囊壳,野生型PH-1可以。本研究初步表明,FGSG09482基因对禾谷镰孢菌菌落的生长速率有一定的调控作用;对禾谷镰孢菌的分生孢子的产量、子囊壳的产生也有影响,推测FGSG09482基因可能与禾谷镰孢菌有性生殖、无性生殖过程相关。     

Genomic footprints of wheat evolution in China reflected by a Wheat660K SNP array

Common wheat(Triticum aestiuum L.)is one of the most important crops because it provides about 20%of the total calories for humans.T.aestiuum is an excellent modern species for studying concerted evolution of sub-genomes in polyploid species,because of its large chromosome size and three well-known genome donors.Establishment of common wheat genome reference sequence and development of high-density SNP chips provide an excellent foundation to answer questions of wheat evolution and breeding at the genomic level.By genotyping more than 600 accessions of common wheat and their diploid and tetraploid ancestors using a Wheat660 K SNP array,we found dramatic genome changes due to tetraploidization and hexaploidization,in contrast to weaker influences of domestication and breeding on them.Further,since common wheat was introduced in China in 1500 BCE,Chinese landraces formed two subgroups(T.aestiuum-L1 and T.aestiuum-L2)with considerably diverse geographic distributions and agronomic traits.T.aestiuum-L2,mainly distributed in central and east China is found to have more but smaller oval grains with early maturity characteristics.We found that variation and selection in intergenic regions of the A and B sub-genomes dominated this differentiation,in which chromosomes 7 A and 3 B took the leading roles due to the existence of putative genes related to defense responses and environmental adaption in the highly differentiated regions.Large haplotype blocks were detected on 3 B(232.6-398.3 Mb)and 7 A(211.7-272.9 Mb)in the landraces,forming two distinct haplotypes,respectively.We discovered that artificial crosses in breeding promoted recombination in the whole genome,however,this recombination and differentiation was highly asymmetric among the three sub-genomes in homoeologous regions.In addition,we found that the wide use of European and northern American cultivars in breeding at early era,led dramatic changes in Chinese wheat genome,whereas,the recent breeding functioned to optimize it.This study will provide the insight for reconsideration of wheat evolution and breeding,and a new strategy for parent selection in breeding.     

军犬处突解救人质

一,案发现场的特点 一般绑架人质现场分为两种：一是隐蔽型,指案犯将人质劫持后隐蔽起来,其特点是地点偏僻,流动人员较少,大多是发生在郊区的民房、废弃的厂房、建筑工地等;二是公开型,指案犯在公开场所劫持人质,在大庭广众之下向有关方面提出某些要求。     

Exogenous application of melatonin improves plant resistance to virus infection

In this study, melatonin (MEL)-mediated plant resistance to tobacco mosaic virus (TMV) was examined to study local infection in Nicotiana glutinosa and systemic infection in Solanum lycopersicum. Exogenous application of 100 µm MEL increased anti-virus infection activity to 37.4% in virus-infected N. glutinosa plants. The same treatment significantly reduced relative levels of virus RNA analysed by qRT-PCR and virus titres measured by dot-ELISA, and increased the relative expression levels of the PR1 and PR5 genes analysed by qRT-PCR, in virus-infected S. lycopersicum. MEL treatment induced considerable accumulations of salicylic acid (SA) and nitric oxide (NO) but did not significantly affect production of hydrogen peroxide (H₂O₂) in the virus-infected S. lycopersicum plants. Transgenic nahG N. tabacum was used to determine whether MEL-induced TMV resistance was dependent on the SA pathway. The results showed that the relative RNA level of the TMV analysed by qRT-PCR and virus titres analysed by dot-ELISA were not reduced by the MEL treatment in the nahG transgenic N. tabacum seedlings treated twice with 100 µm MEL. The increased relative expression levels of PR1 and PR5 were greatly reduced when cPTIO, an NO scavenger, was included in the MEL treatment. A working model of MEL-mediated plant resistance to TMV is proposed. MEL-mediated plant resistance to viruses provides a new avenue to control plant viral diseases.     

温室甲鱼养殖生石灰的合理使用

生石灰是水产养殖的一种常规药物,非常普遍的用在水质消毒,疾病防治中,许多水产养殖用户也把生石灰作为一种常用的水质改良剂,但在甲鱼的养殖中,要根据情况酌情使用,否则,会出现pH值过高从而导致有毒气体的产生,造成甲鱼中毒的病况。本文介绍了温室甲鱼养殖中生石灰使用不当引起的病况,并提出了相应解救措施。实验中采用了生石灰日常消毒常用的浓度和间隔日期,伴随着pH值与氨氮的浓度升高,甲鱼出现了死亡现象,在解除了生石灰的使用后,甲鱼停止了死亡现象。     

义乌城市防护绿地建设的宏观生态途径

“义乌盆地”的地理和气候易造成污浊空气在城市内沉积,也不利于外围新鲜空气进入城区。义乌在建设了大量的城市防护绿地的同时,选择了一条独特的宏观生态途径,理顺和打通了城市进气和排气通道,并进一步提出完善城市防护绿地宏观生态体系的几点举措。     

Effects of dietary fish oil replacement with blended vegetable oils on growth,lipid metabolism and antioxidant capacity of subadult swimming crab Portunus trituberculatus

A 120‐day trial was conducted to assess the effects of dietary fish oil replacement with vegetable oils on growth, lipid metabolism and antioxidant capacity of subadult swimming crab Portunus trituberculatus. Five isonitrogenous and isolipidic diets were formulated to replace 0, 250, 500, 750 and 1000g/kg of fish oil with a mixture of soybean and rapeseed oil (defined as D1–D5), and each treatment had 30 replicate crabs. Dietary fish oil replacement had no significant effects on growth of the crabs, while the D3 had the highest hepatosomatic index and total lipids in hepatopancreas. The triglyceride and lipase activities in hepatopancreas increased significantly with increasing dietary fish oil replacement. The D4 had the highest levels of alkaline phosphatase (ALP) and acid phosphatase (ACP) in the hepatopancreas, as well as the haemolymph ALP, ACP and peroxidase. The highest levels of haemolymph total antioxidant capacity, catalase and malondialdehyde were detected in D1. Total n‐3 polyunsaturated fatty acids levels in hepatopancreas decreased significantly with increasing dietary fish oil replacement. In conclusion, dietary fish oil replacement had no significant effects on growth of P. trituberculatus, and 500g/kg of fish oil replacement could improve antioxidant capacity, but excessive replacement level will enhance lipid accumulation and peroxidation in the hepatopancreas.