太平洋牡蛎2龄贝的生长

通过１９９８扑３月 １２月对太平洋牡蛎２龄贝生长进行测定得出：壳高在４～６月初生长最快;７月、１２月为出肉率最高时期;７月末８月初为２龄贝产卵期。     

Studies on Selective Uptake Behavior of Hg(II) and Pb(II) by Functionalized Poly(Ethylene Terephthalate) Fiber with 4-Vinyl Pyridine/2-Hydroxyethylmethacrylate

The adsorption behavior of 4-vinyl pyridine and 2-hydroxyethylmethacrylate grafted poly(ethylene terephthalate) fiber toward the Hg(II) and Pb(II) ions in aqueous solutions was studied by a batch equilibration technique. The influence of the treatment time was considered as well as the pH of the solution, the initial metal ions concentration, the graft yield, and the temperature. Such parameters as the adsorption kinetics, the adsorption isotherm, and the desorption time were further studied. Maximum adsorption occurred at pH 3 and pH 6 for Hg(II) and Pb(II), respectively. The adsorption kinetics followed the mechanism of the pseudo-second-order equation for heavy metal ions. The adsorption data is a good fit with Freundlich isotherm. Desorption studies indicated that the maximum percent recovery of Hg(II) and Pb(II) was 93.4% and 76.3%, respectively with 1 M HNO₃.     

The effect of dietary n‐3 series fatty acids on the number of pleopadal egg and stage 1 juvenile in freshwater crayfish,Astacus leptodactylus Eschscholtz

The effect of dietary n‐3 series fatty acids on the number of pleopadal egg and stage 1 juvenile in freshwater crayfish, Astacus leptodactylus was investigated. Crayfish were fed with n‐3 series fatty acids supplemented diets and a control diet for 251 days. Control diet did not comprise additional n‐3 series fatty acids. However, D2, D3 and D4 groups were supplemented with n‐3 series fatty acids at 1%, 2% and 3% level respectively. Results showed the beneficial effects of dietary n‐3 series fatty acids on the production of pleopodal egg and stage 1 juvenile number. At the end of the experiment, pleopodal egg (from 177 to 234) and stage 1 juvenile number (from 167 to 225) increased significantly with increased dietary n‐3 series fatty acid level. In addition, an increase in dietary n‐3 series fatty acids led to an increase in number of pleopodal egg and stage 1 juvenile produced per gram of female crayfish weight. It can be concluded that the reproductive efficiency of A. leptodactylus (i.e., pleopodal egg and stage 1 juvenile number) can be improved in controlled hatchery conditions by adding n‐3 series fatty acid into the diet of this species.     

Quality Changes in Marinated Anchovy (Engraulis encrasicolus) Sauced with Olive Oil-Lemon Juice Emulsions

ABSTRACT

This study describes the potential use of olive oil-lemon juice emulsions containing different levels of lemon juice (0, 25, 35, and 50% v/v) as a flavoring, preservative, and antioxidant agent in marinated anchovy. The phenolic content and antioxidant activity of lemon juice, olive oil, and olive oil-lemon juice sauces as well as chemical, oxidative, and sensorial changes of marinade samples were analyzed. Increasing the level of lemon juice in sauces retarded the chemical and oxidative changes of marinated anchovy. However, increasing the level of lemon juice more than 35% in sauces led to a decrease in sensorial acceptability. Chemical and oxidative qualities of all the sauced samples were in the limit of deterioration during 100 days of storage. Although marinated anchovy samples treated with sauce containing 50% lemon juice had a significant inhibitor effect on chemical and oxidative deterioration, samples treated with sauce containing 35% lemon juice received the highest overall acceptability score.     

人参皂苷生物合成的相关酶及其基因的研究进展

人参皂苷生物合成主要通过2,3一氧化鲨烯的环化作用、羟基化作用、苷化作用,经类异戊二烯途径被合成。异戊烯二磷酸经栊牛基二磷酸酶、鲨烯合成酶、鲨烯环氧酶催化作用形成2,3一氧化鲨烯,再经氧化鲨烯环化酶作用形成各种类型的三萜类化合物,三萜类又在细胞色素P450和糖基转移酶作用下形成各种类型的人参皂苷。本文重点介绍人参皂苷生物合成的相关酶及其基因,为进一步深入研究奠定了基础。     

不同施药模式对小麦产量、品质及效益的影响

为优化小麦病虫害防控技术,2008-2010年在成都平原开展了不同施药模式(CK:孕穗期和开花期喷施清水;T1:在孕穗期和开花期喷施杀菌剂防治病害;T2:在孕穗期和开花期喷施杀虫剂防治虫害;T3:在孕穗期和开花期分别喷施杀菌剂和杀虫剂防治病虫害;T4:在开花期一次性混合喷施杀虫剂和杀菌剂防治病虫害)试验,分析了不同处理间小麦病虫害、产量、品质及效益的差异。结果表明:(1)多数测试指标存在显著的年度效应,锈病病株率、白粉病病株率、降落值和多数RVA参数存在显著的年度与处理互作效应;(2)对照处理病虫害发生较重,单独喷施杀虫剂或杀菌剂均不能有效防控病虫危害,分次或混合施用杀虫剂和杀菌剂对病虫害的综合防控效果明显好于单独喷施;(3)施药处理较对照都有明显的增产、增收效果,产量增加6.9%～11.8%,纯收益增加4.3%～8.7%,以杀虫剂和杀菌剂分次喷施处理增幅最大;(4)施药处理对不同品质指标的影响存在较大差异,施药有降低湿面筋含量、沉降值和面团稳定时间的趋势,但都明显提高了降落值和RVA参数值。施药处理均未检出农药残留限值。综合产量、品质和效益,在选择抗病品种的基础上,于开花期实施多类药剂混合喷施不失为小麦节本高效的病虫防控措施。     

QTL hotspots in eggplant (Solanum melongena) detected with a high resolution map and CIM analysis

Fifty-eight F₂ individuals derived from an interspecific cross between cultivated eggplant, Solanum melongena, and its wild relative, S. linnaeanum, were phenotyped for 42 plant, leaf, flower, and fruit traits. Composite interval mapping analysis using genotypic data from 736 molecular markers revealed the positions of 71 statistically significant (P ≤ 0.05) quantitative trait loci (QTL) influencing 32 of the morphological traits. Although most QTL were location-specific, QTL governing three traits (leaf lobing, leaf prickles and prickle anthocyanin) were detected in both experimental locations. Analysis of three additional traits (stem prickles, fruit calyx prickles and fruit length) in both locations yielded QTL in similar but non-overlapping map positions. The majority (69 %) of the QTL corresponded closely with those detected in previous analyses of this data set. However the increased resolution of the linkage map combined with advances in QTL mapping permitted more precise localization, such that the average interval length of these QTL was reduced by 93 %. Thirty-one percent of the QTL were novel, suggesting that simple linear regression with a low density linkage map (the method used in previous studies of this population) missed a substantial portion of significant QTL. Hotspots of QTL affecting plant hairiness, prickliness, and pigmentation were identified on chromosomes 3, 6, and 10, respectively, and may reflect the pleiotropic activity of single structural or regulatory genes at these positions. Based on synteny between the eggplant, tomato, potato and pepper genomes, putative orthologs were identified for 35 % of the QTL suggesting strong conservation of gene function within the Solanaceae. These results should make it easier to target particular loci for map-based cloning and marker-assisted selection studies.     

糖化工艺参数对膨化小麦辅料麦汁收得率的影响

为提高低温挤压膨化小麦辅料麦汁收得率, 优化糖化工艺,对水料比、辅料比、50℃蛋白质休止时间、62℃糖化时间、70℃糖化时间5因素进行Box Behnken中心组合试验设计,用响应曲面法分析各参数对麦汁收得率的影响。试验得到的最佳糖化工艺参数为: 水料比416(V/m),膨化小麦比例为310%,50℃蛋白质休止时间50 min,62℃糖化时间50 min,70℃糖化时间30 min,在上述条件下,麦汁收得率可达6971%。     

Effects of dietary l-tryptophan on the agonistic behavior,growth, and survival of freshwater crayfish Astacus leptodactylus Eschscholtz

In this study, the effects of dietary tryptophan (a precursor of 5-hydroxytryptamine, 5-HT, serotonin) on the agonistic behavior, growth, and survival of freshwater crayfish were investigated. For this aim, a control diet (D1) and three experimental diets (D2, D3, and D4) were prepared. D1 contained no additional tryptophan (TRP), but D2, D3, and D4 diets were supplemented with TRP at 0.50, 0.75, and 1.00 % in dry diet, respectively. The control contained 0.33 % TRP. Results revealed that higher supplemental dietary TRP levels caused a significant decrease in the aggressive behavior (P < 0.05), but an increase in the calmness of crayfish. In addition, the results showed that 5-HT levels in the hemolymph before the fight (after 15 days of feeding; resting) were significantly different (P < 0.05) between D1 and D4. There was a significant difference (P < 0.05) in the 5-HT level of hemolymph between the crayfish fed control and D4 after 15 days of feeding. However, after the fight, 5-HT concentration was significantly higher (P < 0.05) in TRP-supplemented A. leptodactylus as compared with the control. The findings of this study showed that supplemental dietary TRP caused a significant increase (P < 0.05) in the growth and survival rate of A. leptodactylus. The crayfish fed D4 had the best survival rate at the end of the experiment (91.60 % in August). The findings of this study also showed that difference in survival rate between the crayfish fed control and D2 in June, July, and August was not significant (P > 0.05). In addition to these, supplemental dietary TRP gave rise to significantly higher specific growth rate (SGR) values in June and July (P < 0.05). For example, in June, it was 0.38 for the crayfish fed D4, 0.28 for the crayfish fed D3, 0.18 for the crayfish fed D2, and 0.13 for the crayfish fed control. However, in August, the highest SGR (0.56) was obtained from the crayfish fed control. The results also showed that the SGRs of females were lower than the males in June, July, and August (P < 0.05). In conclusion, this research shows that the aggressive behavior of A. leptodactylus can be suppressed, and rearing efficiency (i.e., increased growth and high survival rate) of this species can be improved by increasing TRP levels to 1.00 % in its diet.