木醋液对桃蚜生长繁殖的急慢性效应

为了明确木醋液对桃蚜短、长期影响,以桃蚜为试虫,用100倍稀释木醋液处理小白菜饲养蚜虫,测得桃蚜繁殖发育数据。结果显示,木醋液处理显著缩短桃蚜繁殖期,而F₁代繁殖期比F₀代繁殖期延长37%;F₀代和F₁代产蚜总量与对照组相比分别降低62%和66%;处理组F₁代和F₂代的存活率比对照组降低23%和24%,但F₁代和F₂代之间差异不显著;F₁代寿命缩短25%,F₂代差异不显著。本研究证明木醋液能够缩短桃蚜的繁殖期,延长其若蚜历期,整体缩短桃蚜寿命,降低子代存活率。总之,木醋液对桃蚜的生长发育和繁殖具有一定的抑制作用,但是这种抑制作用会随着施用频次增加而逐渐减弱,即木醋液的短期效应和长期效应存在差异,所以木醋液具有开发为生物农药的价值。     

豫皖小麦田麦根腐平脐蠕孢交配型基因检测

麦根腐平脐蠕孢是一种可以引起多种植物病害的病原真菌，广泛分布于世界各地，对全世界的禾谷类作物生产带来了不可估量的损失。子囊菌交配型基因具有一定的广泛性，其编码的产物是调控子囊菌有性生殖的重要转录因子。为了对河南、安徽小麦田分离获得的麦根腐平脐蠕孢群体的MAT基因型进行探索，对在河南、安徽两省不同地区分离获得33株麦根腐平脐蠕孢菌株，利用麦根腐平脐蠕孢菌的MAT特异性引物进行基因型检测，并对不同交配型代表菌株进行生长形态、孢子形态观察和致病力测定，对麦根腐平脐蠕孢菌 MAT-2基因进行了系统发育分析。结果表明，河南、安徽两省存在两种MAT基因型的麦根腐平脐蠕孢群体，含有 MAT-2基因的菌株21株，含 MAT-1基因的菌株12株，比例为7∶4（ MAT-2∶ MAT-1）。两种交配型菌株的生长形态、孢子形态和致病力无显著差异，整体分析结果与物种的分子系统学分析表现出来的亲缘关系基本一致。     

Nile tilapia broodfish fed high‐protein diets: Digestive enzymes in eggs and larvae

The aim of this study was to assess the activity of gastric, pancreatic and intestinal digestive enzymes during the embryonic and larval development of Nile tilapia (Oreochromis niloticus) GIFT strain Aqua America^® 1 obtained from a broodstock fed two levels of crude protein (CP). A total of 72 females and 24 males, 10 hapas, two CP levels (32% and 38%) and six phases of embryonic (cleavage, blastula, gastrula) and larval (hatching, 7 and 10 days post hatch, dph) stages were used. The eggs were collected in cleavage, blastula and gastrula stages, 300 mg was collected, and kept in cryogenic tubes in liquid nitrogen. For the samples at larval stage, the remaining eggs were separated according to crude protein level and kept in hatcheries and samples were collected on 7 and 10 dph the same way as before. A total of 48 samples were collected: at each protein level (32% and 38% CP), four samples were collected in each phase of embryonic and larval development. Statistical differences were not observed during embryonic development for acid proteases, trypsin, amylase and lipase activity at both levels of crude protein (32 and 38% CP). Differences for acid proteases were noticed on 7 dph; trypsin and amylase on 7 dph and 10 dph. Significant differences on blastula and 7 dph for protease; as for aminopeptidase, there was significant difference on 7 dph. The data indicated early appearance of digestive enzymes in Nile tilapia broodfish receiving 32% CP taking into account the rapid growth and development of this species.     

马尾藻海藻多糖生物活性研究新进展

近年来的研究表明,马尾藻中富含多种新型生物活性化合物,如海藻多酚、海藻多糖及多种硫酸多糖衍生物。在分离出的生物活性成分中,海藻多糖因其具有良好的保健作用和药用效果而备受关注。同时,有大量研究已经证明,马尾藻海藻多糖对人类疾病的预防以及恢复具有积极效果。因此,本文对近年来马尾藻海藻多糖的抗凝血、抗氧化、抗肿瘤、抗血管生成和抗炎症活性的最新进展进行了综述,以期能助推马尾藻海藻多糖的研究,并且协助填补理论研究与工业应用之间的知识鸿沟。     

Assessment of short-term mortality of granary weevil,Sitophilus granarius (Coleoptera: Curculionidae) triggered by different microwave irradiation powers

Abstract

The insecticidal efficacy of microwave irradiation against the at 12, 24, 48 and 72?h following exposure to microwave irradiations (100, 300?W) and the progeny production was assessed 45?days later. Linearly increasing irradiation power range (100, 200 and 300?W) was set up for determining mortality tendency. An increase of insect mortality caused by higher irradiation period and times elapsed after treatment has become evident commencing from 12?h after the treatment, which has significantly decreased at later elapsed time after treatment. The irradiation periods inducing the highest mortality at the examined powers were at 10?min and at 100?W power (72?h: 64.93%) and at 4.5?min. and at 300?W power (12?h: 87.01). In addition, a complete suppression of progeny production was achieved by 4.5?min treatment at 300?W power. Lognormal-type mortality process was caused by the linearly increased irradiation range. The properly chosen microwave irradiation can be used for management of Sitophilus granarius larval and adult developmental stages. This treatment could provide an effective and friendly environmental treatment technique in Integrated Pest Management (IPM) program.     

木薯有性四倍体遗传稳定性分析

木薯作为中国重要的经济作物,其优良品种的选育一直是木薯科研工作的重点,而多倍体的巨型性特点为其育种提供了新的思路,目前多倍体研究大多是体细胞加倍,有性多倍化研究起步较晚,而本课题组通过2n配子有性活体杂交,成功获得了首例木薯有性四倍体植株。为了研究木薯有性四倍体的遗传稳定性,本研究分别采用:田间的农艺性状观测(生长稳定期)、流式细胞术、叶片染色体计数、蛋白质含量测定/蛋白质聚丙烯酰胺凝胶电泳以及淀粉含量测定等方法进行鉴定。结果显示:木薯有性四倍体各株系农艺性状均保持了母株器官巨型性的多倍体特征;流式细胞仪分析显示,木薯有性四倍体各株系叶片DNA含量均为二倍体亲本(SC5)的两倍,相对应的叶片染色体数目也为二倍体亲本(SC5)的两倍,且视野中四倍体细胞所占比例均在90%以上;各株系蛋白质含量均小于二倍体对照组,且有性多倍体株系电泳谱带基本相似;在淀粉含量测定中,其各株系淀粉含量均小于对照组,且各株系之间含量波动较小。本研究结果表明木薯有性四倍体植株具有较好的遗传稳定性,对木薯多倍体品种的选育具有重要意义。     

Effect of ascorbic acid supplementation on zootechnical performance,haematological parameters and sperm quality of lebranche mullet Mugil liza

The feed provided to breeding fish is one of the main factors influencing the quality of fish gametes. This study was carried out to evaluate the influence of ascorbic acid on growth, haematological parameters and sperm quality of Lebranche mullet males (Mugil liza). Six diets with different levels of ascorbic acid (0; 53; 107; 216; 482 and 708 mg/kg) were tested in triplicate for 75 days. During spermiation (first gonadal maturation), 144 individuals (205.7 ± 11.5 g and 25.7 ± 0.4 cm) were randomly distributed in 18 experimental tanks. Growth parameters were evaluated at the beginning and end of the experiment. Fish blood was collected to analyse glucose, total protein and erythrocyte count (EC) (n = 9). Fish (n = 12) from each treatment were euthanized to determine hepatosomatic index (HSI) and gonadosomatic index (GSI). Semen was collected to evaluate spermatic density, cell membrane integrity and sperm motility. No difference (p > .05) was found on growth parameters, GSI, HSI and total protein. However, EC was lower in fish fed without ascorbic acid (the control group). Ascorbic acid supplementation provided positive effects on sperm characteristics. Fish from treatments with 53 and 107 mg/kg presented the best results for motility time (133.30 ± 4.25 and 135.00 ± 2.77 respectively). Treatments with 107, 216 and 708 mg/kg provided the best results for motility rate (92.0 ± 2.9%, 93.0 ± 5.8% and 93.0 ± 5.8% respectively). Supplementation with 107 and 216 mg/kg provided the best results for plasma membrane integrity (70.12 ± 9.10% and 76.3 ± 3.1% respectively). Lower spermatic density was observed in fish without ascorbic acid supplementation, although no difference was found in sperm density among the treatments with ascorbic acid (p < .05). Considering these results, supplementation of dietary ascorbic acid between 107 and 216 mg/kg optimizes the spermatic quality in males of lebranche mullet.     

Possible involvement of PKC/MAPK pathway in the regulation of GnRH by dietary arachidonic acid in the brain of male tongue sole Cynoglossus semilaevis

Our previous studies have indicated that dietary arachidonic acid (ARA) significantly affects the gonadal steroidogenesis in the marine teleost tongue sole Cynoglossus semilaevis, and this effect was more positive in male fish than in female fish (Aquaculture, 468, 378–385). As a following up study, the present study was further aimed at investigating the possible mechanisms in the brain mediating the effects of dietary ARA on gonadal steroidogenesis. A 70‐day feed trial was repeated with two‐year‐old tongue sole, using three experimental diets with graded levels of ARA, 0.34%, 2.53%, and 9.63% of total fatty acids. Each diet was fed to triplicate groups of 23 fish (15 males and 8 females). The results confirmed the positive effect of dietary ARA on testosterone production in male fish. The concentration of gonadotrophin‐releasing hormone (GnRH) in serum responded to dietary ARA in a similar pattern with the testosterone concentration, but the concentration of gonadotrophin in serum was not affected by dietary ARA. The response of gene expression of PKCβ, ARRB1, ARRB2, ERK2 and ATF3 in the brain to dietary ARA was in good agreement with those of GnRH and testosterone, indicating the possible involvement of PKC‐ARRB‐ERK‐ATF3 pathway in signalling transduction of GnRH. However, the PI3K/Akt and TLR/NF‐κB pathways may not be directly involved in the regulation of GnRH metabolism by ARA. This is the first study reporting the possible involvement of PKC/MAPK pathways in regulation of reproductive endocrine processes by long‐chain polyunsaturated fatty acid in brain of marine fish.     

Abnormal development of genital organs in offspring male mice exposed to finasteride during pregnancy

AIM: To investigate the effects of finasteride exposure during pregnancy on the development of reproductive organs in offspring male mice. METHODS: CD-1 mice were treated with finasteride from 0 to 17 d after conception. The development of reproductive organs in the offspring male mice were observed by macroscopy, anatomical analysis and histological staining. The spermatogenesis was analyzed by immunofluorescence staining. RESULTS: Macroscopic observation showed that fenasteride exposure during pregnancy resulted in external genital malformations in the offspring male mice, which were manifested as incomplete scrotal fusion and penile malformation. In addition, the anogenital distance was significantly shortened (P<0.01). Histological staining showed that the length of penis at each stage was significantly shortened (P<0.01), the density of seminiferous tubules in testis and mature spermatozoa in seminiferous tubules were significantly decreased (P<0.01), and the luminal space size of seminiferous tubules and interstitial space size of testises were significantly increased (P<0.01). Immunofluorescence staining showed that the densities of Sertoli cells, Leydig cells and spermatogonium in testis were significantly reduced (P<0.01), and the fluorescence intensity of caspase-3 in spermatogenic tubule cells was increased significantly (P<0.01). However, the fluorescence intensity of Ki67 and desert hedgehog (Dhh) was decreased significantly (P<0.01). CONCLUSION: Finasteride exposure during pregnancy results in abnormal development of reproductive organs in offspring male mice and affects spermatogenesis.