Diversity,plant growth-promoting traits,and biocontrol potential of fungal endophytes of Sorghum bicolor

The diversity of fungal endophytes in Sorghum bicolor was investigated in samples collected from 10 different geographical regions of Karnataka state, India. A total of 360 endophytes were isolated from leaf, stem, and root tissues and were assigned to 26 fungal species based on morphology and molecular characterization using ITS sequences. All the endophytes belonged to the phylum Ascomycota. The diversity (Shannon H, 2.57; Simpson_1-D, 0.92) and species richness (Margalef's, 4.68; Menhinick, 3.61) were found to be higher for the endophytes isolated from leaf tissues. The species evenness of the endophytic assemblage was strongly influenced by tissue type, followed by geographical location. The biocontrol potential of isolated endophytes was evaluated against economically destructive sorghum grain mould pathogens such as Fusarium thapsinum, Epicoccum sorghinum, Alternaria alternata, and Curvularia lunata using the dual culture method. Biocontrol potential was exhibited by 26 endophytic isolates, of which Trichoderma asperellum recorded broad-spectrum activity against target pathogens, followed by E. nigrum and A. longipes. Most (82%) endophytes showed plant growth-promoting traits. Biosynthesis of indole-3-acetic acid (IAA) was observed in 84% of isolates, and phosphate solubilization, siderophore production, and cellulase activity was observed in 69%, 23%, and 27% of isolates, respectively. Seeds treated with T. asperellum exhibited a significantly higher seed vigour index (2096), germination percentage (94%), and yield under greenhouse and field conditions. The results were substantiated by the confocal microscopy analysis, which clearly demonstrated the colonization of treated endophyte in root tissues. The present study reveals an ecofriendly approach to explore T. asperellum in sorghum disease management.     

5种农药低空喷雾防治黄脊竹蝗成虫效果分析

为确定低空喷雾无公害药剂防治黄脊竹蝗成虫的林间最佳浓度水平和用药量，掌握低空喷雾施药技术，在福建省三明市三元区的毛竹林建立试验区，应用无人机开展低空喷雾防治试验。结果表明：药后7 d，5种农药的防治效果均超过90%，其林间最佳浓度水平（药剂与纯净水的体积比）为：1.5%苦参碱可溶液和1.2%烟碱·苦参碱乳油均为1：1 000；25%阿维·灭幼脲悬浮剂为1：700，1%苦参·藜芦碱可溶液和4%鱼藤酮乳油均为1：600，原药量用为900 mL/hm²。5种农药防治效果良好，可推广应用于防治黄脊竹蝗成虫。     

Agronomic traits at the seedling stage,yield, and fiber quality in two cotton (Gossypium hirsutum L.) cultivars in response to phosphorus deficiency

ABSTRACT

Cotton is critical for phosphorus demands and very sensitive for its deficiency. However, identifying the effect of low-phosphorus tolerance on cotton growth, yield, and fiber quality by reducing phosphorus consumption. This may help to develop phosphorus-tolerant high-yielding cotton cultivars. In a two-year repeated (2015 and 2016) hydroponic experiment (using 0.01 and 1 mM KH₂PO₄), two cotton cultivars with phosphorus sensitivity (Lu 54; a low-phosphorus sensitive and Yuzaomian 9110; a low-phosphorus tolerant) were screened on the base of agronomic traits and physiological indices through correlation analysis, cluster analysis and principal component analysis from 16 cotton cultivars. Low phosphorus nutrition reduced the plant height, leaf number, leaf area, phosphorus accumulation and biomass in various organs of seedlings. The deficiency negatively affected the morphogenesis of seedlings, as well as yield and fiber quality. Further, these screened cultivars were tested in a pot experiment with 0, 50, 100, 150, 200 kg P₂O₅ ha^?1 during 2016 and 2017. It was found to have a significant (P< 0.05) difference in boll number, lint yield, fiber strength, and micronaire at the harvest. Furthermore, after collectively analyzed the characteristics of Lu 54 and Yuzaomian 9110, there were six key indices that could improve the low phosphorus tolerance of cotton cultivars. These were root phosphorus accumulation, stem phosphorus accumulation percentage, leaf and total biomass of seedlings, seed cotton weight per boll and fiber length.     

贵州省不同年代糯高粱品种（系）农艺性状演变分析

以贵州省不同年代酿酒用糯高粱品种（系）为研究对象,采用随机区组试验设计,对其农艺性状、产量构成以及抗性差异进行分析,结果表明：随着年代更替,贵州省酿酒用糯高粱单产逐步提高。新品种（红缨子、黔高8号）较老品系（黑壳糯、红壳糯）平均单产增幅25%以上;穗粒数、穗粒重增加显著,增幅分别为51.7%、62.7%;主穗一、二级枝梗数增加幅度分别为19.8%、62.7%;株高降低24.9%,茎粗增加9.5%;节间数增加0.9个,节间长缩短13.3cm;单株叶面积和叶面积指数增加显著;倒伏率、发病率下降显著,成穗率明显提升。各指标相关性分析显示,产量与穗粒数、穗粒重,穗粒数与主穗一、二级枝梗数呈极显著正相关;产量与株高、倒伏率极显著负相关,与茎粗正相关,相关系数分别为-0.981、-0.970和0.928,株高、茎粗与倒伏率相关显著,相关系数分别为0.964和-0.910;产量与叶面积指数正相关,与发病率显著负相关。总的结果表明,主穗一、二级枝梗数的增加提高了糯高粱的穗粒数,植株株高的降低、茎粗的增加促进了抗倒性的提升,抗病性的提升保证了后期叶片光合作用的持续进行,最终提高了糯高粱产量。     

常见蜜源植物花卉开发利用研究进展

蜜源花卉是指供蜜蜂采集花蜜和花粉的花,其生物资源非常丰富。因其含有多种营养物质及生物活性物质,而具有药食两用性。目前我国对于蜜源花卉的开发利用并不广泛,以致多数蜜源花卉在农副产业中被当作废弃物,随着绿色科学的发展,人们逐渐意识到蜜源花卉具有广阔的开发价值。本文就常见的蜜源花卉研究进行综述,分析其主要成分、以及常用的分离纯化技术,旨在为蜜源花卉高效利用提供依据。     

植物生长调节剂、基质对三个品种费约果扦插生根的影响

选取五年生健壮费约果树为母株，采用L9(33)正交设计法研究植物生长调节剂、基质对三个品种费约果半木质化枝条扦插生根的影响。本试验结果表明：不同品种、植物生长调节剂和基质处理的生根的影响呈显著性水平。影响费约果扦插枝条生根率因素的主次顺序为品种>植物生长调节剂>基质；影响根长因素的主次顺序为基质>植物生长调节剂>品种；影响插穗根数的因素主次顺序品种>基质>植物生长调节剂。Gemini品种经1000 mg/L ABT浸泡两分钟，以腐叶土+珍珠岩为基质，生根效果最好，生根率为70.00%，平均根长为8.85 cm，平均根数为10.22条/穗；Unique品种经1000 mg/L ABT浸泡两分钟，以腐叶土+蛭石为基质，生根效果较好，生根率为56.67%，平均根长为9.32 cm，平均根数为12.33条/穗；Coolidge品种生根率低，均≤20 %。     

UCP1基因变异与绵羊生长及胴体性状的关联分析

试验旨在探讨解耦联蛋白1（UCP1）基因核苷酸变异对绵羊生长性状的性别差异和胴体性状的影响，以期能够筛选出可以提升绵羊生长及胴体性状的核苷酸变异，为提高绵羊相关重要经济性状的分子遗传标记提供材料。以9个绵羊品种为研究对象，用PCR-SSCP方法检测不同性别绵羊中UCP1基因内含子5区和外显子6区变异。利用Minitab 16.0软件中一般线性模型分析内含子5区等位基因与不同性别绵羊生长性状、公羔胴体性状的关联性。结果显示，绵羊UCP1基因内含子5区和外显子6区共检测到8个核苷酸变异，其中位点c.910 G/A突变导致p.Ala304Thr氨基酸变异。生长性状关联分析结果表明，内含子5区等位基因对绵羊生长性状的影响存在性别特异性，母羔中携带等位基因A₁的群体较缺失群体具有较低的初生重（P<0.05），公羔中携带等位基因C₁的群体较缺失群体具有较高的断尾重（P<0.05），未发现其他等位基因与羔羊的生长性状存在性别特异性。胴体性状关联分析结果表明，携带等位基因A₁的群体具有较低后腿瘦肉量、腰部瘦肉量和较高的肩部瘦肉比例（P<0.05），携带等位基因C₁的群体具有较低的后腿瘦肉比例（P<0.05），其他胴体性状均没有发现与等位基因存在显著相关，基因型分析结果与等位基因分析结果一致。结果提示，UCP1基因对绵羊的生长性状影响具有性别特异性，且携带等位基因A₁的公羔群体具有较低的胴体生产性状，为提高公羔胴体生产性能提供了理论依据。     

硅钙钾镁肥配施黄腐酸钾对土壤酶活性及桃幼树生长的影响

为探究硅钙钾镁肥配施黄腐酸钾对桃树生长的效应,以盆栽一年生瑞蟠21号毛桃(Amygdalus persica Linn.)为试验材料,设置3种不同施肥方式(T1:硅钙钾镁;T2:硅钙钾镁+黄腐酸钾;CK:空白对照),在桃幼树生长季进行追肥处理,研究硅钙钾镁肥及硅钙钾镁肥配施黄腐酸钾对土壤酶活性、土壤养分状况及桃幼树根系构型和植株生长的影响。结果表明,与CK相比,T1、T2均显著提高了桃幼树生长季各时期土壤酸性磷酸酶、脲酶和过氧化氢酶活性,以及土壤中碱解氮、有效磷、速效钾和有效硅等含量,且配施黄腐酸钾后作用更明显。与CK相比,T1、T2细根比重分别提高了11.2%和26.2%,根系活力分别提高了12.2%和18.1%,根系总长度分别增加了28.1%和61.9%,且有效延缓了根系衰老;T1、T2植株总干重分别提高了1.2倍和2.0倍,根冠比分别提高了9.4%和17.0%,且差异显著。与CK相比,T1、T2各器官中全氮、全磷、全钾含量均显著增加,地上部硅含量分别提高了61.3%和91.9%,地下部硅含量分别提高了62.3%和102.5%,且差异显著。同时,T1、T2桃幼树叶片叶绿素含量和净光合速率均显著提高。综上所述,硅钙钾镁肥可有效提高土壤酶活,促进桃幼树细根的生长,延缓根系衰老进程,增加氮、磷、钾、硅等营养元素积累量,提高叶片光合速率,促进植株生长;硅钙钾镁肥配施黄腐酸钾后,提高了土壤有效硅及植株硅含量,比单施硅钙钾镁肥效果更加显著。本研究结果为桃树合理施用硅钙钾镁肥提供了理论依据。