日光温室黄瓜新品种津优33号的选育

津优33号是以优良自交系P4和242杂交而成,植株生长势强,叶片中等大小,深绿色,主蔓结瓜为主;低温(8~10℃)弱光(8000lx)条件下能够正常开花结果,且瓜条生长速度快,坐瓜率高;抗黄瓜霜霉病、白粉病和灰霉病;瓜条长30~32cm,心腔小于瓜横径的1/2,瓜把较短,刺瘤密,瓜条深绿色,有光泽,口感脆嫩,品质好,单瓜质量175g,每667m2产量6000kg左右,适于日光温室越冬栽培。     

Weed flora of water rice in the Red River Delta,Vietnam

The occurrence of weeds in water rice was surveyed in the Red River Delta, Vietnam during spring and summer rice-growing seasons in 1995 and 1996. Sixty different weeds from 19 plant families were recorded. The most important plant families as weeds of rice were Poaceae and Cyperaceae. The most important weed however was Rotala indica (Willd.) Koehne (Lythraceae) followed by Echinochloa crus-galli (L.) Beauv. and Cyperus difformis L. A brief comparison of this rice weed flora and those of Australia and California was made.     

Changes in fineroot growth dynamics in response to phosphorus application in an Acacia mangium plantation in Vietnam

Fineroots (≤ 2 mm diameter) are dynamic components of the forest ecosystems and play important role in water and nutrient acquisition in forests. These roots are sensitive to forest fertilization and therefore, the response of fineroots to nutrient application would provide better understanding of the forest carbon and nutrient dynamics that will be helpful in sustainable forest management plans. Two fertilization treatments, including (1) F400: 400 g P₂O₅ (16.5%)/tree and (2) F600: 600 g P₂O₅ /tree, and F0: control (without fertilization), were applied in an Acacia mangium plantation with a planting density of 1100 trees/ha (3 m?×?3 m). The evaluation of fineroot growth across seasons showed that fertilization significantly increased production and subsequent mortality and decomposition. The total decomposition associated with F600 application was 7.95 tons ha^?1 year^?1, equaling 121% of F400 and 160% of the control. Mortality in F600 was 8.75 tons ha^?1 year^?1, equaling 111% of F400 and 198% of F0, while production in F600 was 10.40 tons ha^?1 year^?1, equaling 127% of F400 and 143% of F0. Fineroot production, mortality, and decomposition are seasonally dependent, with higher values measured in the rainy season than in the dry season. Stand basal area increment was significantly correlated with fineroot production (R²?=?0.75), mortality (R²?=?0.44), and decomposition (R²?=?0.48). This study showed that fertilization could facilitate fineroot production, which can then lead to a higher turnover of carbon and nutrients through the decomposition of the greater mass of the fineroots.

     

Production of silkworms with conjugated linoleic acid (CLA) incorporated into their lipids by dietary CLA

Silkworms with conjugated linoleic acid (CLA) incorporated into their lipids (designated CLA silkworms) were produced to enhance the quality of silkworms having a synergistic effect with CLA functions by dietary synthetic CLA. Silkworm larvae were fed fresh mulberry leaves (control diet) until the third instar stage and were then subjected to various levels (0%, 0.1%, 1%, 5%, and 10%) of CLA-sprayed mulberry leaves (designated CLA diet) beginning on the first day of the fourth instar stage and continuing to the third day of the fifth instar stage. CLA contents in CLA silkworms increased proportionally with increasing CLA levels of CLA diets. CLA silkworms on a 1% CLA diet contained 2.2 g CLA/100 g lipid without body weight reduction, whereas CLA silkworms on a 10% CLA diet contained 14.8 g CLA/100 g lipid with a significant reduction of body weight, relative to the control silkworms. The CLA content in the lipids of CLA silkworms on a 10% CLA diet was significantly higher than that of CLA silkworms on a 5% CLA diet. A 0.1% CLA diet was not sufficient to accumulate CLA in the silkworms. Most of the CLA (approximately 99%) of silkworm lipids was present in triglyceride (TG) with a similar ratio of c9,t11 and t10,c12 CLA isomers. These results suggest that a 1% CLA diet was suitable for the production of CLA silkworms.     

我国农用植保无人机的应用现状及展望

随着我国农业的发展,机械化、自动化是未来发展的趋势,尤其是在平原地区更应该得到大范围的推广和应用。在美国、德国等农业体系发达的国家都已经采用了机械自动化的农业发展,以高科技器械代替人工种植、喷洒农药、收割作物等行为,不仅取得了较高的农业生产效率和产量外,也将人们的劳动力得到进一步的发展。在我国当前的农业发展过程中,农用植保无人机正处于推广应用的阶段,其使用的价值和机械收割机、插秧机同样重要,帮助农民减轻工作量,大大提高我国农业的发展,并与国际接轨。本文通过对于我国农用植保无人机的使用情况进行分析,根据当前我国的农业发展展望未来的农用植保无人机发展,充分得出农用植保无人机对于我国农业进步具有重要意义,不仅能够重新构架我国农业体系的形成,而且对于农业机械化产生助力作用,提高我国农业在世界的地位,创造更多的经济价值。     

The impact of a school-based nutrition education intervention on dietary intake and cognitive and attitudinal variables relating to fruits and vegetables

OBJECTIVE: To assess the impact of a school-based nutrition education intervention aimed at increasing the consumption of fruits and vegetables. DESIGN: The intervention programme increased the provision of fruits and vegetables in schools and provided a range of point-of-purchase marketing materials, newsletters for children and parents, and teacher information. Curriculum materials at age 6-7 and 10-11 years were also developed and utilised. Evaluation was undertaken with groups of younger (aged 6-7 years) and older (aged 10-11 years) children. Methods included 3-day dietary records with interview and cognitive and attitudinal measures at baseline, with follow-up at 9 months, in intervention and control schools. SETTING: The work was undertaken in primary schools in Dundee, Scotland. SUBJECTS: Subjects comprised 511 children in two intervention schools with a further 464 children from two schools acting as controls. RESULTS: Children (n=64) in the intervention schools had an average increase in fruit intake (133+/-1.9 to 183+/-17.0 g day(-1)) that was significantly (P<0.05) greater than the increase (100+/-11.7 to 107+/-14.2 g day(-1)) estimated in children (n=65) in control schools. No other changes in food or nutrient intake were detected. Increases in scores for variables relating to knowledge about fruits and vegetables and subjective norms were also greater in the intervention than in the control group, although taste preferences for fruits and vegetables were unchanged. CONCLUSIONS: It is concluded that a whole school approach to increasing intakes of fruits and vegetables has a modest but significant effect on cognitive and attitudinal variables and on fruit intake.     

农产品物流增值环节的挖掘

随着信息化的发展,现代农产品物流是将存储、运输、包装、流通加工、配送等各个环节与信息技术和网络连接起来,形成一条真正意义上的增值链。本文在分析我国现有农产品物流在增值方面存在问题的基础上,构建了信息平台下的农产品物流模式,深入挖掘了农产品物流的增值环节,提出了农产品物流增值的措施与看法。     

国槐SSR-PCR反应体系的建立与优化

利用单因素试验结合L₁₆（4⁵）正交试验设计对国槐SSR-PCR反应体系中的5个主要影响因素(Mg²⁺、引物、dNTPs、ExTaq酶、模板DNA用量)进行优化,确定最佳反应体系为（10μL）:25 mmol/L Mg²⁺1.0μL,2.5 mmol/L dNTPs 0.2μL,10μmol/L上下游引物共0.5μL,5 U/μL ExTaq酶0.05μL,30 ng/μL模板DNA 1.0μL,10×PCR Buffer 1.0μL,ddH₂O 6.25μL。随机挑选4对SSR引物和8个国槐种质对试验确定的最佳反应体系进行验证,均能获得清晰、稳定的条带。该优化反应体系的建立为利用SSR标记对国槐种质资源进行深入研究和利用奠定了基础。     

Effects of Co‐culture of Cumulus Oocyte Complexes with Denuded Oocytes During In Vitro Maturation on the Developmental Competence of Cloned Bovine Embryos

This study evaluated the effects of co‐culture of immature cumulus oocyte complexes (COCs) with denuded immature oocytes (DO) during in vitro maturation on the developmental competence and quality of cloned bovine embryos. We demonstrated that developmental competence, judged by the blastocyst formation rate, was significantly higher in the co‐cultured somatic cell nuclear transfer (SCNT+DO, 37.1 ± 1.1%) group than that in the non‐co‐cultured somatic cell nuclear transfer (SCNT‐DO, 25.1 ± 0.9%) group and was very similar to that in the control IVF (IVF, 38.8 ± 2.8%) group. Moreover, the total cell number per blastocyst in the SCNT+DO group (101.7 ± 6.2) was higher than that in the SCNT‐DO group (81.7 ± 4.3), while still less than that in the IVF group (133.3 ± 6.0). Furthermore, our data showed that mRNA levels of the methylation‐related genes DNMT1 and DNMT3a in the SCNT+DO group were similar to that in the IVF group, while they were significantly higher in the SCNT‐DO group. Similarly, while the mRNA levels of the deacetylation‐related genes HDAC2 and HDAC3 were significantly higher in the SCNT‐DO group, they were comparable between the IVF and SCNT+DO groups. However, the mRNA levels of HDAC1 and DNMT3B were significantly higher in the SCNT+DO group than in the other groups. In conclusion, the present study demonstrated that co‐culture of COCs with DO improves the in vitro developmental competence and quality of cloned embryos, as evidenced by increased total cell number.     

Feed management for Pacific white shrimp Litopenaeus vannamei under semi‐intensive conditions in tanks and ponds

To improve feed management strategies for the semi‐intensive culture of Litopenaeus vannamei, outdoor tank and pond trials were conducted. In the tank trial, shrimp (35 shrimp/m², n = 4) were offered feed for 6 weeks based on a standard feeding protocol (SFP, designed as T100) with five variations (T80:90:100, T90, T90:100, T100:110, T110) of this protocol produced by varying the feed inputs and expressing the treatments as a percentage. Results demonstrated no significant differences in survival rate and feed conversion ratio (FCR) among treatments. The mean final weight and final biomass in the treatments T100:110 and T110 were significantly higher than those in treatment T90 but were not different from the other treatments. In the pond trial, juvenile shrimp (28 shrimp/m², n = 4) were stocked into twelve 0.1‐ha ponds over a 16‐week period. Three feeding protocols were evaluated including a SFP, a 10% reduction in the SFP (SFP:90), and a variable feed input (SFP:80:90:100), which included 80% SFP at week 4th–8th, 90% SFP from week 9th–12th and 100% SFP for week 12th–16th. There were no significant differences in growth performance and economic return among treatments. Based on previous studies, in which higher feed inputs were evaluated, and results of this study, it does not appear to be economically beneficial to use high feed inputs. Instead, feed input could be either applied at a standard ration to optimize growth and economic return or at restricted rations to reduce FCR (feed cost) albeit at the expense of some growth.