10个甘蔗品种染色体核型分析与比较

通过10个甘蔗品种的核型分析,研究其染色体组成系统演化和血缘构成的基本特征,为甘蔗育种选配亲本提供细胞学依据。以10个甘蔗品种的根尖为材料,采用改良的酶解去壁低渗法制备染色体标本,再利用Ikaros软件进行核型分析。‘粤糖86-368’的核型公式为2n=111=2M+103m+4sm+2T,‘桂糖11’的核型公式为2n=106=96m+10sm,这2个品种的核型分类均属于1B型;‘新台糖10’的核型公式为2n=108=98m+10sm,‘新台糖16’的核型公式为2n=111=4M+101m+6sm,‘新台糖20’的核型公式为2n=110=98m+10sm+2st,‘新台糖22’的核型公式为2n=110=2M+96m+12sm,‘粤糖93-159’的核型公式为2n=108=2M+88m+18sm,‘闽糖69-421’的核型公式为2n=109=95m+14sm,‘云蔗89-151’的核型公式为2n=111=91m+20sm这7个品种的核型分类均属于2B型;‘云蔗99-91’的核型公式为2n=108=84m+22sm+2st,核型分类属于2C型。研究结果说明,‘粤糖86-368’、‘桂糖11’这2个品种的进化程度都还比较原始;‘云蔗99-91’、‘云蔗89-151’进化程度最高;其余6个品种进化程度中等。     

耐氨固氮菌对黄瓜种子萌发、幼苗素质和保护酶活性的影响

采用耐氨固氮菌浸种处理黄瓜种子.结果表明,用2%菌液浸处理黄瓜种子,黄瓜种子发芽势、幼苗素质及子叶保护酶活性均有显著提高,幼苗子叶抗氧化功能增强,其中以浸种时间为3、4 h的效果尤为明显.     

Harvesting European knowledge on soil functions and land management using multi‐criteria decision analysis

Soil and its ecosystem functions play a societal role in securing sustainable food production while safeguarding natural resources. A functional land management framework has been proposed to optimize the agro‐environmental outputs from the land and specifically the supply and demand of soil functions such as (a) primary productivity, (b) carbon sequestration, (c) water purification and regulation, (d) biodiversity and (e) nutrient cycling, for which soil knowledge is essential. From the outset, the LANDMARK multi‐actor research project integrates harvested knowledge from local, national and European stakeholders to develop such guidelines, creating a sense of ownership, trust and reciprocity of the outcomes. About 470 stakeholders from five European countries participated in 32 structured workshops covering multiple land uses in six climatic zones. The harmonized results include stakeholders’ priorities and concerns, perceptions on soil quality and functions, implementation of tools, management techniques, indicators and monitoring, activities and policies, knowledge gaps and ideas. Multi‐criteria decision analysis was used for data analysis. Two qualitative models were developed using Decision EXpert methodology to evaluate “knowledge” and “needs”. Soil quality perceptions differed across workshops, depending on the stakeholder level and regionally established terminologies. Stakeholders had good inherent knowledge about soil functioning, but several gaps were identified. In terms of critical requirements, stakeholders defined high technical, activity and policy needs in (a) financial incentives, (b) credible information on improving more sustainable management practices, (c) locally relevant advice, (d) farmers’ discussion groups, (e) training programmes, (f) funding for applied research and monitoring, and (g) strengthening soil science in education.     

不同肥料处理对甘蔗产量性状、糖分及效益的影响

为解决化肥用量过多问题,提高甘蔗节本增效,选取云南省6个主要蔗区作为试验点,以B9菌剂、有机肥、复混肥不同组合为供试肥料设置不同施肥处理,探讨各肥料处理对甘蔗生长、产量、糖分等农艺性状的影响,并分析甘蔗种植效益。结果表明,施用B9菌剂组合的肥料不同程度促进甘蔗出苗;6个试验点中除盈江县和景谷县施用B9菌剂组合的肥料对促进甘蔗分蘖作用不明显外,其他4个试验点均达到有效促进;与普通复混肥处理相比,施用B9菌剂的处理在株高、茎径、有效茎数、蔗茎产量、蔗糖分等性状有一定程度的增加,但影响不显著。选取元江县进行经济效益分析,结果表明,施用B9菌剂组合的肥料比对照收益高,而没有B9菌剂组合的肥料比对照低。综上所述,施用“B9菌剂+有机肥+化肥”组合的肥料在稳产减肥（化肥）方面起到了积极的作用,值得应用推广。     

Pathological and microbiological characterization of mastitis in dairy cows

Mastitis may be caused by a wide range of microorganisms able to induce distinct lesions in mammary tissues. This study aims to characterize the gross and microscopic features of mastitis in dairy cows and to correlate them with the pathogens involved. The udders of slaughtered dairy cows were inspected and milk samples from each mammary quarter or fragments of the parenchyma were sent for microbiological analysis, and tissue collected for histopathological evaluation. A total of 148 cows and 592 mammary quarters were collected. From these, 432 quarters (73%) had mastitis and in 160 (27%), no changes were observed. Mastitis was classified into seven patterns based on the histopathological findings, of which mixed, lymphoplasmacytic, and suppurative mastitides were the most prevalent with 35.9% (155/432), 27.1% (117/432), and 14.3% (62/432) of the cases, respectively. These patterns were associated with the same set of pathogens: Streptococcus spp., coagulase-negative Staphylococcus (CNS), Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis, and Corynebacterium bovis. The pyogranulomatous pattern represented 7.2% (31/432) of the cases with distinct distribution based on the agent involved, mostly S. aureus and Nocardia sp. Abscedative mastitis accounted for 6.0% (26/432) of the cases; it was characterized by multiple abscesses in the parenchyma and was mainly caused by Trueperella pyogenes. Necrosuppurative mastitis represented 5.8% (25/432) of the cases which were characterized by severe parenchyma necrosis and were caused by bacteria such as CNS and Escherichia coli. The granulomatous pattern represented 3.7% (16/432) of the cases and was occasionally associated with Mycobacterium sp.

     

Colletotrichum gloeosporioides, a new causal agent of citrus post-bloom fruit drop

Citrus post-bloom fruit drop (caused by Colletotrichum acutatum) frequently occurs in the southwestern region of São Paulo State, Brazil. A survey of Colletotrichum isolates associated with symptoms of post-bloom fruit drop in São Paulo State showed C. gloeosporioides in addition to C. acutatum. The objectives of this study were to confirm the identification of C. gloeosporioides isolated from symptomatic citrus flowers, to test the pathogenicity of C. gloeosporioides isolates, to compare the development of disease caused by C. gloeosporioides and C. acutatum, and to determine the frequency of C. gloeosporioides in a sample of isolates obtained from symptomatic flowers in different regions of São Paulo State. Through the use of species-specific primers by PCR, 17.3% of 139 isolates were C. gloeosporioides, and the remaining 82.7% were C. acutatum. The pathogenicity tests, carried out in 3-year old potted plants of sweet oranges indicated that both species caused typical symptoms of the disease including blossom blight and persistent calyces. Incubation periods (3.5 and 3.9 days, respectively, for C. acutatum and C. gloeosporioides) and fruit sets (6.7 and 8.5%, respectively for C. acutatum and C. gloeosporioides) were similar for both species. The incidences of blossom blight and persistent calyces were higher on plants inoculated with C. acutatum than in those inoculated with C. gloeosporioides. Conidial germination was similar for both species under different temperatures and wetness periods. Under optimal conditions, appressorium formation and melanisation were higher for C. gloeosporioides than for C. acutatum. These results indicated that Colletotrichum gloeosporioides is a new causal agent of post-bloom fruit drop.     

Organic practices intensify the microbiome assembly and suppress root-knot nematodes

Journal of Pest Science - Roots can recruit beneficial microorganisms to suppress plant pathogens. However, conventional and organic practices differently shape the soil microbiome and consequently...     

甘蔗及甘蔗近缘属内生菌的筛选、鉴定与功能研究

为进一步挖掘甘蔗栽培种及其亲缘野生种中内生菌的功能与价值,筛选出具有促进植物生长功能活性的微生物菌株,用于促进甘蔗产业的增收增产。以前期分离纯化获得的589 株甘蔗内生细菌为基础,筛选并鉴定具有固氮、溶磷、解钾等促生长特性的功能菌株。在此基础上,对菌株产生的有机酸、吲哚乙酸(IAA)和嗜铁素也进行了定量测定与种类划分。结果表明:共有12 株功能菌株被筛选得到,分别编号为B7、B9、C9、D5、E12、F5、G3、H5、J8、L9、M3、O9,其中多株菌株同时具有固氮溶磷解钾等生物学活性;12株菌株分别属于Pantoea、Pseudomonas、Enterobacter、Serratia、Acinetobacter和Bacillus 6个属。进一步功能研究结果表明:菌株G3与C9对于无机磷和有机磷的溶解能力较强,溶磷量分别为1 386.97±331.96与2 523±68.17 mg/L;菌株M3解钾能力较强,解钾量为8.59±0.08 mg/L;各菌株所产生的有机酸主要为酒石酸,其次为苹果酸、乳酸、乙酸、柠檬酸;12株功能菌株可产生IAA及嗜铁素,但产生嗜铁素的种类随菌株而异;各菌株与甘蔗种苗共培养过程中均能促进甘蔗种苗芽长与根长的生长,其中表现较优的有E12、C9、G3菌株处理组。该研究可为后续微生物菌肥开发奠定材料基础,也为相关研究提供参考。     

甘蔗作为能源作物的优势分析及前景展望

与其他能源作物相比,能源甘蔗在原料供应、乙醇产量、生产成本及加工技术等方面具有明显优势,发展前景广阔。能源乙醇生产有利于蔗糖产业的持续发展,促进农业产业结构调整,稳定和提高农民收入。当前,发展甘蔗燃料乙醇产业应重视解决品种选育、工艺改进、政策扶持等问题。