Genomic evaluation for novel stayability traits in Nellore cattle     

Pedro Vital Brasil Ramos  Fabyano Fonseca e Silva  Luiz Otávio Campos da Silva  Gustavo Garcia Santiago  Gilberto Romeiro de Oliveira Menezes  José Marcelo Soriano Viana  Roberto A. A. Torres Júnior  Andrea Gondo  Luiz F. Brito 《Reproduction in domestic animals》2020,55(3):266-273

Cow stayability plays a major role on the overall profitability of the beef cattle industry, as it is directly related to reproductive efficiency and cow's longevity. Stayability (STAY63) is usually defined as the ability of the cow to calve at least three times until 76 months of age. This is a late-measured and lowly heritable trait, which consequently constrains genetic progress per time unit. Thus, the use of genomic information associated with novel stayability traits measured earlier in life will likely result in higher prediction accuracy and faster genetic progress for cow longevity. In this study, we aimed to compare pedigree-based and single-step GBLUP (ssGBLUP) methods as well as to estimate genetic correlations between the proposed stayability traits: STAY42, STAY53 and STAY64, which are measured at 52, 64 and 76 months of cow's age, considering at least 2, 3 and 4 calving, respectively. ssGBLUP yielded the highest prediction accuracy for all traits. The heritability estimates for STAY42, STAY53, STAY63 and STAY64 were 0.090, 0.151, 0.152 and 0.143, respectively. The genetic correlations between traits ranged from 0.899 (STAY42 and STAY53) to 0.985 (STAY53 and STAY63). The high genetic correlation between STAY42 and STAY53 suggests that besides being related to cow longevity, STAY53 is also associated with the early-stage reproductive efficiency. Thus, STAY53 is recommended as a suitable selection criterion for reproductive efficiency due to its higher heritability, favourable genetic correlation with other traits, and measured earlier in life, compared with the conventional stayability trait, that is STAY63.  相似文献   

A sublethal concentration of afidopyropen suppresses the population growth of the cotton aphid,Aphis gossypii Glover (Hemiptera: Aphididae)          下载免费PDF全文

MA Kang-sheng  TANG Qiu-ling  LIANG Ping-zhuo  LI Jian-hong  GAO Xi-wu 《农业科学学报》2022,21(7):2055-2064

The cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is an important insect pest of cotton crops worldwide. The objectives of this study were to determine the acute toxicity of afidopyropen and whether there are any effects of sublethal concentrations of afidopyropen on the biological characteristics of A. gossypii. The results showed that afidopyropen possesses high acute toxicity to adult A. gossypii with a 72 h LC₅₀ value of 1.062 mg L^–1. A sublethal concentration (LC₁₀) of afidopyropen significantly decreased adult longevity, fecundity and oviposition days of female adults in both F₀ and F₁ generations. The total pre-adult survival of F₁ progeny was also significantly reduced by 30% at the LC₁₀ of afidopyropen. In addition, the nymph developmental time, pre-adult period, adult pre-reproductive period (APRP), and total pre-reproductive period (TPRP) of the F₁ progeny were significantly prolonged compared with the control. Several population parameters, including the net reproductive rate (R₀), intrinsic rate of increase (r) and finite rate of increase (λ) of F₁ progeny were significantly decreased by a sublethal afidopyropen concentration exposure. These results indicated that sublethal concentration of afidopyropen can significantly suppress A. gossypii population growth. It would be useful for assessing the overall effects of afidopyropen on A. gossypii.  相似文献   

温度对松突圆蚧匀鞭蚜小蜂发育与繁殖影响的研究     

何国锋  卢爱平  包为民 《昆虫天敌》1995,(2)

松突圆蚧匀鞭蚜小蜂Encarsia sp.在1989年从日本引进到广东,在室内能用茶钹盾蚧Abgrallaspiscyanophylli来大量繁殖。在25～28℃恒温下,发育历期为23～26天,成蜂寿命1～3天,与温度关系密切。成蜂羽化高峰在羽化后的第2～4天,每日的羽化高峰在12时～20时.此蜂是产雌性孤雌生殖,在30.04℃下,能产卵和完成发育,但子代成蜂寿命仅数小时;当温度在32.01℃时,成蜂仍可产卵和幼虫早期能发育,在33.03℃时,幼虫则不能发育;在适温条件下,平均每天产卵4.3±5.8粒。  相似文献   

Genotype by environment interaction for length of productive life in Swedish Red and White dairy cattle     

Karl-Johan Petersson  Rebecka Kolmodin  Erling Strandberg 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(1):9-15

In this study the amount of genotype by environment interaction (G×E) for length of productive life of Swedish Red and White dairy cattle was studied. The environmental variables used were the herd-year averages of number of first parity cows, peak yield, protein yield, and productive life. Data were analysed using multi-trait models (using low and high quartile herds) and reaction norm models (using the whole continuous scale). Considerable G×E was found for the trait productive life between environments (herds) with short or long average productive life, and a genetic correlation of 0.74 was found. For productive life in relation to herd size, G×E was negligible, and the genetic correlation was 0.95. For productive life in relation to herd-year average of peak yield or protein yield some G×E was indicated by the reaction norm model, especially between extreme environments. The G×E between herds with short or long average productive life should be studied further and might need to be considered in breeding programmes for dairy cattle.  相似文献   

Occurrence of two localMegastigmus species parasitic on the eucalyptus gall waspLeptocybe invasa in Israel and Turkey     

Alex Protasov  Miktat Doĝanlar  John La Salle  Zvi Mendel 《Phytoparasitica》2008,36(5):449-459

Two localMegastigmus species were found to be parasitoids on the invasive Eucalyptus gall waspLeptocybe invasa Fisher & La Salle in Turkey and Israel.Megastigmus sp, from Israel is a larval and pupal parasitoid ofL. Invasa. Both species are biparental. Features showing morphological differences between them are presented. The biology, distribution and potential efficiency as biological control agents are discussed.  相似文献   

温度、盐分和储藏时间对多花柽柳种子萌发的影响   总被引：4，自引：0，他引：4  

王磊  严成  魏岩  尹林克 《干旱区研究》2008,25(6)

通过研究储藏时间、温度以及不同浓度NaCl溶液对多花柽柳种子萌发的影响,结果表明:多花柽柳种子褐色,棒状,长(0.368±0.005)mm,宽(0.172±0.004)mm,千粒重(20.518±2.500)mg;种子寿命约240 d;在5/15 ℃,5/25 ℃,15/25 ℃和25/35 ℃(光/暗=12/12 h)4个温变周期下,多花柽柳新成熟种子的萌发率均在90%以上,且彼此间差异不显著;盐分浓度小于0.2 mol/L时不抑制种子萌发,大于0.6 mol/L时萌发率随盐浓度的增高而降低,直至为零,且复水后恢复萌发率低,表明NaC1处理后的部分种子永久地失去萌发力.最后探讨了多花柽柳种子的萌发行为对荒漠环境的适应意义.  相似文献   

取食不同种类的糖对斑痣悬茧蜂寿命、繁殖力及营养贮存的影响     

胡衡  刘亚慧 《中国生物防治》2014,(2):165-170

寄生蜂成虫可以直接取食含有单糖和二糖的花蜜和蜜露。本文研究了取食葡萄糖、果糖、麦芽糖和甘露糖对斑痣悬茧蜂寿命、繁殖力和营养贮存的影响。结果显示,取食葡萄糖、果糖、麦芽糖和甘露糖后,斑痣悬茧蜂的寿命分别为25.9、21.3、21.5和11.1 d,与对照相比显著增加;平均后代数分别为72.8、51.1、55.8和8.6头,而清水对照只有4.3头,其中取食甘露糖后,斑痣悬茧蜂平均后代数与对照差异不显著。体内主要物质含量测定表明取食糖类后,寄生蜂极大程度地积累总糖,取食葡萄糖、果糖和麦芽糖与水相比寄生蜂体内脂含量显著增加,并随着处理时间延长而增加。但取食甘露糖与水相比寄生蜂体内脂含量显著下降。取食4种糖都在产卵高峰前期蛋白质浓度达到最高,死亡前蛋白质浓度最低,两者之间差异显著。  相似文献   

温度和营养对蝶蛹金小蜂寿命的影响     

王福莲  范佳鸿  李传仁 《湖北农业科学》2008,47(3):307-309

在不同温度和不同营养条件下,测定了蝶蛹金小蜂雌、雄蜂的寿命.结果表明,35℃时雌蜂和雄蜂寿命均最短,分别为4.32 d和3.64 d;5℃时雌、雄蜂寿命均最长,分别为33.80 d和26.86 d;除35℃与30℃间差异不显著外,其他温度间均有显著差异(P=0.05).无营养时雌雄蜂的寿命均最短,仅为6.53 d和2.71 d.饲喂40%蜂蜜水时雌蜂和雄峰的寿命最长,分别达到31.24 d和22.54 d,不同营养处理间有极显著差异(P=0.01).5℃ 40%蜂蜜水、5℃ 20%蜂蜜水和20℃ 40%蜂蜜水组合务件下,雌蜂的寿命较长.分别为45.83 d、44.86d和44.68d;5℃ 40%蜂蜜水组合,雄峰寿命较长,为43.78 d,其次为5℃ 20%蜂蜜水组合,为38,71 d.  相似文献   

不同营养对亚金跳小蜂寿命和适合度的影响     

张娟  唐娅媛  黄俊  吕要斌  李明江 《植物保护学报》2018,45(4):759-765

为了解不同营养对寄生性天敌亚金跳小蜂Aenasius arizonensis(Girault)寿命及适合度的影响,在室内测定了10%蜂蜜水、10%蜂蜜水+粉蚧蜜露、蒸馏水+粉蚧蜜露、粉蚧蜜露和蒸馏水等不同饲喂条件对亚金跳小蜂寿命、雌蜂平均寄生率、羽化率和子代雌性比例的影响。结果表明,不同营养处理均能显著延长亚金跳小蜂的平均寿命,其中以10%蜂蜜水+粉蚧蜜露处理的效果最为显著,其雌、雄蜂平均寿命较对照分别增加3.87 d和1.07 d;不同营养条件下,雌蜂的适合度以10%蜂蜜水+粉蚧蜜露处理最好,雌蜂平均寄生率、羽化率和子代雌性比例分别为对照的12.11、1.84和52.35倍,雌蜂平均寄生率、羽化率和子代雌性比例在4~10 d均维持在较高水平,其最大值分别达80.67%、70.72%和63.74%。表明各种营养条件,尤其以10%蜂蜜水+粉蚧蜜露为营养时可延长亚金跳小蜂寿命,同时能提高其适合度。  相似文献   

Evidence for systemic age underestimation in shark and ray ageing studies          下载免费PDF全文

Alastair Varley Harry 《Fish and Fisheries》2018,19(2):185-200

Numerous studies have now demonstrated that the most common method of ageing sharks and rays, counting growth zones on calcified structures, can underestimate true age. I reviewed bomb carbon dating (n = 15) and fluorochrome chemical marking (n = 44) age validation studies to investigate the frequency and magnitude of this phenomenon. Age was likely to have been underestimated in nine of 29 genera and 30% of the 53 populations studied, including 50% of those validated using bomb carbon dating. Length and age were strongly significant predictors of occurrence, with age typically underestimated in larger and older individuals. These characteristics suggest age underestimation is likely a systemic issue associated with the current methods and structures used for ageing. Where detected using bomb carbon dating, growth zones were reliable up to 88% of asymptotic length (L_∞) and 41% of maximum age (A_Max). The maximum magnitude of age underestimation, Δ_Max, ranged from five to 34 years, averaging 18 years across species. Current perceptions of shark and ray life histories are informed to a large extent by growth studies that assume calcified ageing structures are valid throughout life. The widespread age underestimation documented here shows this assumption is frequently violated, with potentially important consequences for conservation and management. In addition to leading to an underestimation of longevity, the apparent loss of population age‐structure associated with it may unexpectedly bias growth and mortality parameters. Awareness of these biases is essential given shark and ray population assessments often rely exclusively on life history parameters derived from ageing studies.  相似文献