3个四季草莓品种在川西高原栽培研究

以圣安德瑞斯、波特拉和蒙特瑞3种四季草莓为材料,在茂县进行夏季栽培比较试验,通过各品种的农艺性状及果实内、外在品质等指标进行分析对比以及灰色关联度分析,结果表明:圣安德瑞斯的长势最好；圣安德瑞斯的果实虽然大而重但糖酸比较低,口感较差,风味偏酸,蒙特瑞的固酸比最高,风味最好； 3个品种加权关联度排名依次为蒙特瑞、圣安德瑞斯、波特拉。结论：在茂县及相应高原区域栽培条件下,蒙特瑞的综合适应性最佳。     

Beef quality traits of heifer in comparison with steer,bull and cow at various feeding environments

The present review has been focused largely on the sex type differences in beef quality among heifers, cows, steers and bulls in various feeding environments. Genetic groups, feeding systems and gender are the major factors that change carcass characteristics and fatty acid profiles of cattle. Studies identified that heifer beef has super characteristics in eating quality and a better healthy composition in fatty acids than steer, cow and bull. Diet influences the variation of fatty acid profile; particularly the level of polyunsaturated fatty acids (PUFA) interacts with breed and sex. Animals finished in pasture systems were reported to show better ratios of PUFA/ saturated fatty acids and n‐6/n‐3. Carcasses of roughage‐fed beef are lighter and have less marbling and lower quality grades but have higher cutability than carcasses of grain‐fed bulls. Heifers and cows are reported to deposit more fat than steers and bulls. Among males, lower production of testosterone by steers favors more fat thickness compared with bulls. Marbling greatly varies among cattle belonging to different sexes, and particularly, females have genetic makeup that efficiently controls deposition. The current review identified that heifers can be a premium beef brand, while steer beef currently take a large part of market share across the world.     

盐胁迫下外源Ca~(2+)对红豆草幼苗抗性生理的影响

以蒙农红豆草为材料,研究了100mmol/L NaCl胁迫下不同浓度外源Ca2+对红豆草幼苗的生长、脯氨酸、可溶性糖和叶绿素含量及根系活力的影响;探讨了Ca2+对盐胁迫伤害的缓解作用。结果表明:随着Ca2+浓度的增加,与CK相比,红豆草脯氨酸、可溶性糖、叶绿素含量及根系活力呈先升高后降低的明显变化趋势,在T3(100mmol/L NaCl+30mmol/L CaCl2)处理下,红豆草脯氨酸、可溶性糖及叶绿素含量与对照相比提高了32.3%,60.0%和9.7%,差异显著(P0.05);T3、T4处理的根系活力显著高于CK(P0.05),其他处理与CK无明显差异;T3处理的株高显著高于对照CK(P0.05),其他处理与CK间无显著差异,达到最佳的效果。     

不同蛋白质水平饲粮对大巴沙三元杂种猪生长性能和胴体品质的影响

为研究不同蛋白质水平饲粮对大巴沙猪生长性能、胴体品质和肉质的影响,选择体重25 kg左右的大巴沙三元杂种猪36头,随机分成3组,每组2个重复,每个重复6头,公母比例一致。试验分前期(25~60 kg)和后期(60~100 kg)2个阶段。高蛋白质组前期和后期蛋白质水平分别为16.00%和14.02%,中蛋白质组分别为15.00%和13.02%,低蛋白质组为14.00%和12.02%。结果表明,与中蛋白质组、低蛋白质组相比,高蛋白质组全期日增重分别提高5.47%(P0.05)和10.31%(P0.05),全期料重比分别降低3.28%(P0.05)和11.72%(P0.05);3点平均背膘厚分别提高0.56cm(P0.01)和0.29 cm(P0.05);眼肌面积分别提高7.85%和降低3.45%;整个试验期每千克增重成本分别降低0.23元和1.05元。综合考虑,大巴沙三元杂种猪饲粮适宜的粗蛋白质水平为前期15.00%~16.00%、后期13.02%~14.02%。     

Genetic parameters for litter size,piglet growth and sow's early growth and body composition in the Chinese–European line Tai Zumu

Genetics of piglet growth in association with sow's early growth and body composition were estimated in the Tai Zumu line. Piglet and sow's litter growth traits were calculated from individual weights collected at birth and at 3 weeks of age. Sow's litter traits included the number of piglets born alive (NBA), the mean piglet weight (MW) and the standard deviation of weights within the litter (SDW). Sow's early growth was measured by the age at 100 kg (A₁₀₀), and body composition included backfat thickness (BF₁₀₀). A main objective of this study was to estimate separately the direct genetic effect (d) and the maternal genetic effect (m) on piglet weight and daily weight gain during lactation. Variance components were estimated using the restricted maximum likelihood methodology based on animal models. The heritability estimates were 0.19 for NBA, 0.15 and 0.26 for SDW and MW at 3 weeks and 0.42 and 0.70 for A₁₀₀ and BF₁₀₀. The NBA was almost independent from SDW. Conversely, the A₁₀₀ and BF₁₀₀ were correlated unfavourably with SDW (r_g<−0.24, SE<0.12). A stronger selection for litter size should have little effect on litter homogeneity in weights. Selection for lean growth rate tends to favour heterogeneity in weights. The direct effect on piglet weight at birth and daily weight gain accounted for 12% (h² (d) = 0.02) and 50% (h² (d) = 0.11) of the genetic variance, respectively. The association between d and m for piglet weight was not different from zero at birth (r_g = 0.19, SE = 0.27), but a strong antagonism between d and m for daily weight gain from birth to 3 weeks was found (r_g = −0.41, SE = 0.17). Substantial direct and maternal genetic effects influenced piglet growth until weaning in opposite way.     

播期和播量对橘园间作下山黧豆产量及农艺性状的影响

在橘园间作条件下,采用裂区试验设计,经连续两年试验,研究了不同播种期、播种量对豆科绿肥山黧豆(Lath yrus sativus)鲜草产量、种子产量及农艺性状的影响.结果表明,1)播期、播量对山黧豆鲜草和种子产量均有显著影响(P＜0.05),播量影响大于播期;2)山黧豆的鲜草和种子产量随播期推迟显著降低(P＜0.05),9月20日播种的鲜草产量最高,达29 406.0 kg·hm-2,种子产量则以9月30日播种的最高,为1 616.1 kg·hm-2.早播(9月播种)时,株高、单株分枝数、单株根瘤数、结实率和千粒重等农艺性状均优于晚播(10月播种);3)播量为45.0 kg·hm-2时,其鲜草和种子产量均最高,拯种量过大对产量和农艺性状均有负向作用.综上,山黧豆在四川西充与橘园间作下的适宜播种期在9月,最佳播种量为45.0 kg·hm-2.     

北方白菜型冬油菜花器特性及农艺性状与含油量的相关性

为研究北方白菜型冬油菜花冠直径与千粒重及含油量之间的相关性,以20份不同的白菜型冬油菜为材料，测定花器大小、农艺性状、种子含油量及蛋白质含量,并对控制花器特征基因mf6、apetala和myb进行实时荧光定量PCR分析。结果表明:花冠直径受雌蕊直径影响较大,主成分分析提取的3个主成分可综合为花器各性状长度、雌蕊直径和花器各性状宽度；以花冠直径为指示性状，将20份白菜型冬油菜花冠划分为3类群；相关性分析表明，花冠直径与千粒重呈极显著正相关，相关系数0.663；千粒重与含油量呈极显著正相关，与蛋白质含量呈显著负相关。相较于小花，mf6在大花中相对表达量上调了151.63%，而apetala和myb分别下调了83.80%和72.70%。北方白菜型冬油菜品种间花器大小存在显著差异；在育种中可通过增加花冠直径来提高千粒重，进而增加油菜产油量，培育高含油量白菜型冬油菜品种。mf6、apetala和myb基因对白菜型冬油菜花器生长发育均具有一定调控作用。     

Do active‐dispersing insects dominate the invertebrate fauna of rock pools in the wet–dry tropics,Kimberley, Australia?

1. Invertebrate assemblages of tropical freshwater rock pools (FRPs) are poorly known compared with temperate regions, where FRPs contain specialized, endemic taxa of high conservation value. Invertebrates were sampled from pristine FRPs in the Morgan River catchment in the Australian wet–dry tropics in the 2015 and 2016 wet seasons. Taxa were classified as either active or passive dispersers and by functional feeding groups. A range of physical variables were examined to identify associations with invertebrate assemblages.
2. Forty‐seven taxa were identified from FRPs; most were actively dispersing predatory insects, primarily Coleoptera and Hemiptera. Five adult insect species were found in most pools; other taxa were rare and scattered across FRPs. Two previously undescribed species of Spinicaudata were collected, but few crustacean taxa were recorded, and passively dispersing taxa were rare. Species accumulation curves indicated that had more pools been sampled, more taxa would have been collected in 2015, but in 2016 most species were collected.
3. There was no pattern in FRP assemblages related to any physical variable, but the assemblages in pools were correlated between sampling times. An opportunistic and mobile assemblage composed mostly of actively dispersing predatory insects may explain the absence of relationships with measured variables. Low hydrological stability in the wet–dry tropics may be associated with low taxon richness.
4. The dominance of actively dispersing insects is in contrast with FRP assemblages in temperate and arid regions. Studies of a wider range of FRPs from tropical regions are required to determine whether the fauna of these Kimberley FRPs are typical, and to fully describe short‐range endemic species across the Kimberley and elsewhere.
5. The FRPs have conservation value as habitat for endemic, specialist rock‐pool taxa, contributing to regional species pools. At present, a lack of knowledge of endemic FRP specialist species in tropical regions, including the Kimberley, impedes our ability to protect and conserve these species from disturbance.

     

凡纳滨对虾商业苗种抗WSSV性能比较

白斑综合征病毒(WSSV)一直是甲壳类生物的高致病性病原。为了解市场上不同凡纳滨对虾(Litopenaeus vannamei)商业苗种病原携带情况及其抗WSSV性能,本研究收集了6个品牌的凡纳滨对虾商业苗种(分别简称为海南Z、海南S、广州P、广州Z、黄骅R和东营M),先进行包括WSSV在内的8种病原的检测,然后,采用单尾定量口饲感染方式进行抗WSSV性能测试,并比较各组苗种感染WSSV后的平均存活时间、存活率以及累积死亡率的差异。结果显示,6个商业苗种都不携带WSSV,部分苗种检测有潜在虾肝肠胞虫(EHP)和偷死野田村病毒(CMNV)。各苗种感染WSSV后,平均存活时间从长到短依次为海南Z、广州P、黄骅R、海南S、广州Z、东营M。东营M感染WSSV后第4天达到死亡高峰,而海南Z在第6~7天到达死亡高峰,比东营M晚了2~3d。感染实验结束后,海南Z和广州P存活率最高,同为72.5%,而东营M和黄骅R的存活率最低。本研究表明,海南Z和广州P抗WSSV性能最强,研究结果可为凡纳滨对虾抗病新品种的选育提供基础数据。