畜牧领域专业学位研究生“双导师三段制”培养模式探索与思考:以兰州大学为例

畜牧领域专业学位研究生是为畜牧业输送人才的重要途径,进一步完善该领域研究生的培养模式对满足产业人才需求和研究生的职业选择具有重要意义。现行的畜牧领域专业研究生培养过程存在培养方式和产业需求不太匹配、导师队伍实践能力弱和“双导师三段制”培养模式缺少标准等问题。本文从提升导师专业实践能力、系统设计“双导师三段制”培养模式和培养研究生创新创业能力等角度探索和尝试,为提升畜牧领域专业学位研究生理论、实践和创新创业能力提供参考。     

娟姗牛与西杂牛杂交后代生长发育观测

[目的]旨在繁育适于牦牛杂交改良的乳肉兼用父本.[方法]在海拔相对较低的半农半牧区,用娟姗牛与西杂牛杂交,观察杂交后代的生长发育和配种情况.[结果]娟姗牛与西杂牛的杂交后代在甘南州高海拔地区具有较好的适应性,表现出明显的杂交优势,能与甘南牦牛自然交配.     

白木香茎中内源茉莉酸类和倍半萜类物质对机械伤害的响应

 为揭示伤害信号--茉莉酸类（JAs）对倍半萜可能的调控作用,以3年生白木香[Aquilaria sinensis（Lour.）Gilg]树苗为试材进行机械伤害和外施茉莉酸甲酯（MeJA）处理,测定其茎中内源JAs和倍半萜含量。结果表明,机械伤害处理1 h后,内源JAs含量显著增加,随后迅速下降;伤害处理24 h后又有小幅升高。伤害处理诱导白木香产生3种倍半萜（δ–愈创木烯、α–愈创木烯和α–葎草烯）且含量随着伤害时间延长而增多。外源MeJA处理也能够诱导产生相同种类的倍半萜且诱导强度大于伤害处理。伤害早期（1 h）内源JAs含量升高和伤害后期（48 h）倍半萜含量增多是植物启动相应的防御反应和抵御伤害胁迫的重要机制。     

棉枯萎抗性定向培育对棉籽球蛋白与棉紫素的影响

研究了同源的抗枯萎病品种西农87岱16抗和感枯萎病品种原岱16棉花种子的生化成分及其性质差异.结果表明,抗病性不同的两类品种的种子球蛋白的种类,不同分子量球蛋白的合成比率及次生代谢物棉紫素的含量都有较大变化.本项研究结果支持定向培育法是一种科学的棉花抗病育种方法.     

Pregnancy Rate in Zebu Cows with Two Different Postpartum Intervals Exposed to a Two-Bull Rotational System

In order to evaluate the reproductive effect of a rotational breeding system, the pregnancy rate of 69 Zebu cows was assessed, 32 late postpartum (211±93 days postpartum, LP) and 37 early postpartum (averaging 63±8 days after calving, EP). In the LP group, 60% (19/32) were cycling before exposure to the bulls but only 38% (14/37) in the EP group. The two groups were dissimilar from the start (p<0.05). The cows were exposed in a rotational breeding system, with six Brahman bulls with previous sexual experience paired off in three groups (A–B, C–D and E–F). The cows were exposed to each pair of bulls for a period of 3 weeks, with one week in between each period, when the females were without the presence of a male. In the LP group, the pair of bulls A–B obtained a pregnancy rate of 72% (23/32), whereas for bulls C–D the pregnancy rate was 33% (3/9) and for bulls E–F the pregnancy rate was 67% (4/6). In contrast, for the EP cows, bulls A–B obtained a pregnancy rate of 32% (12/37), bulls C–D a pregnancy rate of 67% (12/18) and for bulls E–F a pregnancy rate of 55% (6/11). The percentage pregnancy obtained using the pair of bulls A–B differed (p<0.05) between LP and EP, whereas for bulls C–D and E–F it was similar. The pregnancy rate was different (p<0.05) in the first 3 weeks of mating for the LP group, the highest number of cows becoming pregnant during the first 3 weeks of the study. In contrast, the highest number of pregnancies in EP occurred evenly during the last 6 weeks. This study suggests that the reproductive performance of pairs of bulls in a 9-week rotational programme with the overall pregnancy rate is similar (94% in the LP and 81% in the EP). However, the time taken for the females to become pregnant, and hence the performance of the bulls, is related to the average number of days postpartum for the cows.     

Genetic mapping,marker assisted selection and allelic relationships for the Pu6 gene conferring rust resistance in sunflower

Rust resistance in the sunflower line P386 is controlled by Pu₆, a gene which was reported to segregate independently from other rust resistant genes, such as R₄. The objectives of this work were to map Pu₆, to provide and validate molecular tools for its identification, and to determine the linkage relationship of Pu₆ and R₄. Genetic mapping of Pu₆ with six markers covered 24.8 cM of genetic distance on the lower end of linkage Group 13 of the sunflower consensus map. The marker most closely linked to Pu₆ was ORS316 at 2.5 cM in the distal position. ORS316 presented five alleles when was assayed with a representative set of resistant and susceptible lines. Allelism test between Pu₆ and R₄ indicated that both genes are linked at a genetic distance of 6.25 cM. This is the first confirmation based on an allelism test that at least two members of the R_adv/R₄/R₁₁/ R_13a/R_13b/Pu₆ cluster of genes are at different loci. A fine elucidation of the architecture of this complex locus will allow designing and constructing completely new genomic regions combining genes from different resistant sources and the elimination of the linkage drag around each resistant gene.     

Seasonality and photoperiod influence in vitro production of buffalo embryos

Buffalo is considered short-day breeder in tropical and subtropical part of the world and seasonality and photoperiodism impart major influence on its fertility. However, its impact on in vitro embryo production (IVEP) remains elusive. Therefore, this study investigated the effect of seasonal variations and photoperiodism on morphological and molecular parameters of IVEP in buffalo. For this purpose, we conducted two different experiments on the oocytes obtained by aspirating follicles from abattoir derived ovaries. In Exp. I, retrospective analysis was performed for oocyte recovery, blastocyst and hatching rate, during four consecutive seasonal periods (i.e. January–March, April–June, July–September and October–December). In Exp. II, oocytes from peak breeding and non-breeding seasons were subjected to 24 hr in vitro maturation and evaluated for polar body extrusion to assess maturation rate. Results showed that embryo development was markedly low during second quarter (April–June) and maximum during fourth quarter (October–December) of the year; referred as non-breeding and breeding seasons, respectively. Comparative data analysis demonstrated that poor oocyte quality is major reason for lesser efficiency of embryo production during non-breeding season than peak breeding season as suggested by poor oocyte recovery (2.31 ± 0.10 vs. 3.65 ± 0.27) and maturation rate (33.32 ± 2.1 vs. 63.15 ± 7.31). Subsequently, comparative gene expression analysis of blastocysts during peak breeding season significantly upregulated pluripotency gene (OCT-4) and downregulated heat shock protein 90, as compared to non-breeding season. Therefore, it could be divulged from the present study that seasonal variations and photoperiodism have profound effect on oocyte quality and subsequent embryo development. It is recommended to find suitable additives for in vitro maturation that could mitigate seasonal effects.     

Influence of imported sport horses on the genetic evaluation of Swedish Warmblood stallions

There is substantial international influence on the Swedish Warmblood (SWB) sport horse population. The SWB Association suspects that imported horses are pre-selected based on their anticipated performance level, which could lead to biased estimated breeding values (EBVs) for stallions. This study examined different strategies to handle records for imported horses in the genetic evaluation. The stallions were evaluated for 10 traits using 3 different EBV estimation methods that were compared based on ranking comparisons of stallions, accuracy, correlations and absolute differences between EBVs. The results showed that the stallions’ EBVs were affected by imported offspring which, as a group, had higher average scores than horses born in Sweden. Sire EBVs differed by up to 0.6 genetic standard deviation of the trait between methods for stallions with >50% imported offspring. Excluding imported offspring lowered the accuracies and caused larger re-ranking compared with including a fixed effect of origin in the model.     

不同杀菌剂对当归主要病害的防效及经济效益比较

针对甘肃当归病害逐年加重态势, 采用田间随机区组试验, 分析比较70%噁霉灵WP?50%氯溴异氰尿酸WP和80%代森锰锌WP对当归主要病害防效及经济效益, 以期筛选出最佳防控药剂?结果表明:3种杀菌剂均能不同程度防治当归病害, 其中以50%氯溴异氰尿酸WP 1.86 g/L对褐斑病?麻口病防效最佳, 分别为70.38%~78.75%?84.48%~91.04%, 70%噁霉灵WP 0.34 g/L和80%代森锰锌WP 7.92 g/L次之, 对褐斑病防效分别为59.14%~63.72%?58.14%~62.84%, 对麻口病防效分别为78.61%~83.57%?78.97%~83.57%?50%氯溴异氰尿酸WP 1.86 g/L能很好地抑制当归抽薹, 抑制率达58.63%~63.15%?3种杀菌剂均能明显提高当归药材产量构成因子, 以80%代森锰锌WP 7.92 g/L处理增产增收效果最好, 两年平均增产量高达5 559.91 kg/hm2, 平均经济效益为194 136.65元/hm2, 但投入产出比最低, 为1∶480.63?50%氯溴异氰尿酸WP 1.86 g/L对当归病害防效及抽薹抑制率最高, 投入产出比为1∶634.02, 在此基础上综合考虑病害防效和经济效益, 50%氯溴异氰尿酸WP 1.86 g/L可作为生产上防控当归主要病害的主推药剂?     

植物染色体重排在作物遗传改良中的应用研究进展

染色体重排是一种可能导致DNA片段丢失、重复、易位和倒位的机制,从而改变基因组结构,为创造新的变异性状提供可能。植物染色体重排事件的准确鉴定有助于更深入地理解植物基因组的结构、功能及它们在植物演化和作物育种中的作用。该文深入探讨了植物染色体重排的基本概念,介绍了植物染色体重排的自然发生和人工诱导的技术方法,阐述了植物染色体重排的细胞生物学、分子遗传学和高通量测序鉴定方法。同时,系统总结了植物染色体重排技术在作物遗传育种中的应用,结合具体实践,着重强调了染色体重排技术在提高农作物的遗传多样性、改良农作物的重要性状、增强农作物的环境适应性等方面极具优越性。然而,目前染色体重排的发生概率较低,技术上仍存在挑战,需要更多精准的工具和策略来实现染色体片段的精准定位和重排。通过全面了解染色体重排及其相关技术,研究人员和育种家可以更好地利用植物基因组,为全球粮食安全和环境可持续发展提供创新解决方案。相关研究不仅为深入认识植物基因组提供新途径,也为未来创新作物育种奠定坚实基础。通过挖掘植物基因组的多样性和可塑性,染色体重排技术有望为培育高产、优质、多抗的农作物新品种提供更多可能性,对解决全球日益严峻的...