春白萝卜新品种雪单3 号的选育

雪单3 号是利用双单倍体育种技术选育的春白萝卜新品种。母本ED0108A 是以梅花春萝卜× 白玉春萝卜进行花药培
养获得的DH 系为轮回父本，与不育系进行多次回交，转育成的雄性不育系。父本ED3128 是由迟花春萝卜× 天鸿春萝卜进行
花药培养获得的DH 系。该品种生育期60 d（天），植株开展度45 cm，裂叶，小叶11 对，叶片数20，叶簇平展，叶色深绿；
肉质根长圆柱形，白皮白肉，根长36 cm，横径7.1 cm，单根质量1.1 kg，高抗黑腐病、芜菁花叶病毒病、黄瓜花叶病毒病和花
椰菜花叶病毒病，抗霜霉病，群体整齐度高。每667 m² 产量4 000～5 000 kg。适宜在湖北、湖南、河南、山东等地区早春栽培。     

茄子新品种海丰长茄1 号的选育

海丰长茄1 号是以双单倍体（DH）株系02-QP-19 为母本，优良自交系A-40 为父本配制而成的长茄一代杂种。平
均始花节位为第9 节，植株生长势强，叶片绿色，叶脉、叶柄和主茎的颜色为紫色，植株半开张类型。果实平均纵径31.5
cm，横径4.5 cm，果皮紫黑色，有光泽，果实顶部尖，平均单果质量220 g，VC 和VP 的含量分别为23.2 mg·kg^-1 和0.035%。
一般每667 m² 产量5 000 kg 左右。适宜北京、吉林和黑龙江等地区露地种植。     

C语言在线评价与测试系统的开发与探讨

随着网络教育的发展,接受网络教育和考试认证的人越来越多,在线考试正在得以迅速发展.本文简要介绍在线系统工作原理和系统配置.     

Comparative functional responses of native and high‐impacting invasive fishes: impact predictions for native prey populations

Comparative functional responses (FRs) can predict impacts of invasive species, including piscivorous fishes, via quantifying their depletion of native food resources as a function of prey density. The utility of FRs for predicting impacts on prey populations by invasive fishes of different trophic guilds was tested here by comparing the FRs of the invaders Cyprinus carpio and Carassius auratus, with three native, trophically analogous fishes, Barbus barbus, Squalius cephalus and Tinca tinca. Chironomid larvae and Gammarus pulex were used as prey items. Predictions, developed from studies on the foraging of C. carpio and C. auratus in the literature, were that the invaders would have significantly higher consumption rates for chironomids than the native fishes, but not for G. pulex. Mean consumption rates for chironomids were significantly lower for both invaders than B. barbus and S. cephalus, but were similar to T. tinca. Barbus barbus had a significantly lower consumption rate of G. pulex than both invaders, but there were no significant differences between S. cephalus, T. tinca and the invaders. All FRs were type II, with FR curves for the invaders preying upon chironomids never being significantly higher than the native fishes, contrary to predictions. For G. pulex, some significant differences were apparent between the invaders and native fishes, but again were contrary to predictions. These results indicated that when predation impacts of invasive fishes could also be a function of their population density and body sizes, these parameters should be incorporated into FR models to improve impact predictions.     

不同施肥处理对枳及柠檬容器苗生长的影响

研究9个不同施肥处理对枳及柠檬容器苗生长的影响。结果表明:不同施肥处理对枳容器苗的苗高、地径、分枝高度及嫁接后柠檬苗的发芽率、株高、茎粗、分枝数及生物量都存在显著差异;不同施肥处理对枳及柠檬容器苗综合表现最好的为T4(撒施柠檬专用肥1.6 g)处理,其次是T2(撒施尿素0.6 g)、T3(撒施柠檬专用肥0.8 g)处理,表现最差的是T8(浇施5%柠檬专用肥)和T7(浇施3%柠檬专用肥)处理。在一定施肥浓度范围内,施肥对嫁接后柠檬容器苗的生物量积累有明显促进作用。柠檬容器苗培育时建议采用在基质中撒施柠檬专用肥1.6 g。     

Development of plant‐based diets and the evaluation of dietary attractants for juvenile Florida pompano,Trachinotus carolinus L.

Sustainable and profitable commercial aquaculture production of marine fish species is dependent on the development of sustainable protein sources as substitutes for expensive animal meals such as fishmeal (FM). Previous Florida pompano Trachinotus carolinus studies have indicated that poultry by‐product meal (PBM) and meat and bone meal can be used to produce a FM‐free diet if suitable levels of nutrients (such as taurine) are included in the diets. In this study, we attempted to develop an all‐plant protein diet by removing the animal proteins in practical diets for pompano by substituting back select ingredients. A series of eight FM‐free diets were formulated, four systematically replaced soybean meal (SBM) with soy protein concentrate (SPC) and four replaced PBM with SPC. Based on the results, there is no clear disadvantage to the use of SPC as a replacement for SBM. However, the complete removal of PBM resulted in reduced performance. Two additional growth trials were conducted to supplement additional amino acids including glycine, valine and histidine, a proprietary chemical attractant mix, fish protein concentrate and squid hydrolysate to improve the growth of pompano when fed all‐plant protein diets. The only improvement in performance occurred with the squid hydrolysate. These results demonstrate that using soybean meal, soy protein concentrate and corn gluten meal as the primary protein sources, a plant‐based feed formulation can be developed, but the removal of all animal proteins is not yet feasible.     

Selection of lactic acid bacteria as candidate probiotics for Vibrio parahaemolyticus depuration in pacific oysters (Crassostrea gigas)

The application of probiotics in food is now widespread and is widely accepted by consumers. Lactic Acid Bacteria (LAB) were isolated from traditional salted fish and then characterized by its ability to inhibit Vibrio parahaemolyticus growth using minimal inhibitory concentration tests. Five out of these strains were identified as Lactobacillus delbrueckii, Lactobacillus casei and three Lactobacillus gasseri by PCR using 16S and 23S rRNA genes. Antibiofilm activity of Lactobacillus spp. extracts were also tested in 96 polystyrene plates. A potential antibiofilm effect was demonstrated as most LAB. Although most LAB extract were able to eradicate pre‐formed biofilm, results demonstrated that five Lactobacillus spp. exhibited a stronger inhibitory effect against V. parahaemolyticus in infected oysters. Vibrio parahaemolyticus viable cells number declined from 10⁶ UFC to 10⁴ UFC after 3 days of incubation with Lactobacillus spp. Probiotic applications, in biological control of seafood associated pathogens can be an alternative solution, providing consumer with a product of good quality owing to the use of non‐toxic compounds. Based on our results, LAB could be used as a bioprotective culture in oyster's depuration to prevent V. parahaemolyticus growth.     

Changes in fatty acids profile,monosaccharide profile and protein content during batch growth of Isochrysis galbana (T.iso)

To investigate the nutritional value of the marine micro‐alga Isochrysis galbana Tahitian Isochrysis strain (T.iso) as an alternative feed for aquaculture during culture age, its biochemical composition was studied under autotrophic and controlled culture conditions at different growth stages: exponential phase, early and late stationary phases and decay phase. Analysis showed that C14:0, C16:0, C16:1, C18:4 (n‐3) and C22:6 (n‐3) were the most abundant fatty acids in this alga at different growth stages. The highest values of monounsaturated fatty acids were recorded at the late stationary and the decay phases. However, the highest levels of polyunsaturated fatty acids were observed at the early stationary phase. At all growth stages, I. galbana (T.iso) contained arabinose, xylose, mannose, galactose and glucose. Glucose represented the main sugar, and its content per dry alga biomass weight increased with increasing age of the culture and reached about fourfold in the decay phase. The maximum protein content was also observed during this last phase.     

Bread wheat cultivar PBW 343 carries residual additive resistance against virulent stripe rust pathotype

With continuous outbreaks of stripe rust (Puccinia striiformis f. sp. tritici) epidemics and rapid breakdown of deployed resistance in bread wheat (Triticum aestivum L.) cultivars in North West Plains Zone (NWPZ) in India warrant knowledge and deployment of new and durable sources of resistance to stripe rust. Bread wheat cultivar PBW 343, until recently the most widely cultivated wheat variety in India, is now highly susceptible to stripe rust (score 9 on a 1–9 scale), whereas PBW 621 (score 5.05–5.65) and HD 2967 (score 5.40–6.20) show low levels of resistance. We conducted an experiment, spanning three crop seasons (2013–2014 to 2015–2016), in which parental lines, F₁ and F₂ populations, F₃ and F₄ families from two bread wheat crosses, PBW 621/PBW 343 and HD 2967/PBW 343 were generated and evaluated for stripe rust resistance against a virulent pathotype. While the F₁ revealed partial dominance, the segregation pattern for stripe rust resistance in F₂ and F₃ showed transgressive segregation for resistance in both crosses. Chi-square analysis indicated that resistant segregants possessed two genes, one contributed by PBW 621 or HD 2967 (depending on the cross) and the other, unexpectedly but obviously, came from the most susceptible cultivar, PBW 343. Possible genetic mechanisms for this residual resistance and implications for breeding programs are discussed.     

Breeding for increased grain protein and micronutrient content in wheat: Ten years of the GPC-B1 gene

To provide food and nutrition security for a growing world population, continued improvements in the yield and nutritional quality of agricultural crops will be required. Wheat is an important source of calories, protein and micronutrients and is thus a priority to breed for improvements in these traits. The GRAIN PROTEIN CONTENT-B1 (GPC-B1) gene is a positive regulator of nutrient translocation which increases protein, iron and zinc concentration in the wheat grain. In the ten years since it was cloned, the impacts of GPC-B1 allelic variation on quality and yield traits have been extensively analyzed in diverse genetic backgrounds in field studies spanning forty environments and seven countries. In this review, we compile data from twenty-five studies to summarize the impact of GPC-B1 allelic variation on fifty different traits. Taken together, the results demonstrate that the functional copy of the GPC-B1 gene is associated with consistent positive effects on grain protein, Fe and Zn content with only marginally negative impacts on yield. We conclude that the GPC-B1 gene has the potential to increase nutritional and end use quality in a wide range of modern cultivars and environments and discuss the possibilities for its application in wheat breeding.