绵羊LDHβ基因的生物信息学分析及其在不同剩余采食量绵羊肝脏和肌肉组织中的表达

【目的】为鉴定绵羊乳酸脱氢酶β(lactate dehydrogenase B,LDHβ)基因的分子特征,研究其在不同剩余采食量绵羊肝脏和肌肉组织中的表达差异.【方法】测定了137只‘湖羊’公羔的剩余采食量(residual feed intake,RFI),按RFI进行排序,分别筛选出RFI最高(high-residual feed intake,H-RFI)和RFI最低(low-residual feed intake,L-RFI)的羊各15只,屠宰后,采集肝脏和肌肉组织,利用Q-PCR技术检测绵羊LDHβ基因分别在H-RFI和L-RFI羊肝脏和肌肉中表达量,并利用生物信息学软件构建了该基因的系统进化树和预测其结构与功能.【结果】绵羊LDHβ基因开放阅读框(open reading frame,ORF)为1 005bp,编码334个氨基酸,其蛋白质分子质量为36 479.43U,理论等电点为6.40.绵羊LDHβ基因与山羊的亲缘关系较近,其次为牛,序列同源性高.功能结构域预测结果显示,该基因编码产物在内质网中参与辅酶因子生物合成的可能性最高.Q-PCR结果显示,绵羊LDHβ-mRNA基因在L-RFI羊肝脏和肌肉中表达量均显著低于H-RFI羊(P0.01).【结论】绵羊LDHβ基因作为能量代谢的关键酶参与绵羊饲料效率的调控.     

Reducing tillage intensity affects the cumulative emergence dynamics of annual grass weeds in winter cereals

Annual grass weeds such as Apera spica‐venti and Vulpia myuros are promoted in non‐inversion tillage systems and winter cereal‐based crop rotations. Unsatisfactory weed control in these conditions is often associated with a poor understanding of the emergence pattern of these weed species. The aim of this study was to investigate, understand and model the cumulative emergence patterns of A. spica‐venti, V. myuros and Poa annua in winter cereals grown in three primary tillage regimes: (i) mouldboard ploughing, (ii) pre‐sowing tine cultivation to 8–10 cm soil depth and (iii) direct drilling. Direct drilling delayed the cumulative emergence of A. spica‐venti and V. myuros (counted together) in contrast with ploughing, while the emergence pattern of P. annua was unaffected by the type of tillage system. The total density of emerged weed seedlings varied between the tillage systems and years with a higher total emergence seen under direct drilling, followed by pre‐sowing tine cultivation and ploughing. The emergence patterns of all species were differently influenced by the tillage systems, suggesting that under direct drilling, in which these species occur simultaneously, management interventions should first and foremost consider that A. spica‐venti and V. myuros emerge over a longer period to avoid control failures.     

Regional distribution and integrity of equine ovarian pre‐antral follicles

The goal of this study was to determine the distribution of pre‐antral follicles in the ovarian parenchyma of mares. For Experiment 1, each ovary was cut longitudinally at the greater curvature, performing two hemiovaries. After that, six fragments from each hemiovary were obtained, resulting in 12 fragments, which were divided into the innermost region of the parenchyma, the middle region and the outermost region. All the three obtained sections were cut transversally to obtain two fragments from each one. For Experiment 2, each ovary also submitted to a longitudinal cut on the greater curvature, forming two hemiovaries. Each hemiovary was sectioned into four symmetrical fragments, resulting in eight fragments per ovary. The fragments were related as being near to or far from the ovulatory fossa. The fragments of both experiments were immediately fixed in Carnoy for 12 hr and kept in 70% ethanol for 24 hr. Follicles were classified according to the stages of development and for morphological integrity according to oocyte morphology and granulosa cells. After the histological assessment, a total of 1,130 follicles were visualized from Experiment 1, being 1,054 (93.3%) primordial follicles and 76 (4.7%) follicles in development. The innermost region had the highest percentage of pre‐antral follicles compared to the other regions (p < .05). The middle and outermost regions showed higher percentages of intact primordial and developing follicles than the innermost region (p < .05). Considering Experiment 2, 938 follicles were found, being 894 (95.3%) primordial and 44 (4.7%) follicles in development. The region near the ovulatory fossa presented higher (58.7%; 551 of 938) follicular concentration compared to the region far from the ovulatory fossa (41.3%; 387 of 938; p < .05). As a conclusion, distribution of pre‐antral follicles in the equine ovary has a specific pattern through the parenchyma. Also, the follicular integrity differed in the studied ovarian areas.     

有机氮和无机氮配施对香料烟产值及上部叶品质的影响

在浙江绍兴烟区采用大田试验,研究了在等氮条件下,有机氮部分替代无机氮对香料烟产值及上部叶品质的影响。结果表明,在合适的有机氮和无机氮比例下,有利于香料烟的产量、产值及上等烟比例的提高,上部叶（A1）烟碱、总氮含量的减少,同时有利于上部烟叶总糖、还原糖、糖碱比、钾、氯、矿质元素的增加。对浙江绍兴烟区而言,有机氮和无机氮比例为50∶50时,香料烟产量、产值最高,上部烟叶的品质最好。     

祁连县小麦“3414”肥效试验

在中等肥力的地块进行小麦"3414"肥效试验,结果表明,该立地小麦最佳施肥量为纯N130.7kghm-2,P2O5131.1kghm-2,K2O60.0kghm-2。     

甜菜RAPD反应体系优化及亲缘关系研究

利用正交试验设计,从Mg~(2+)、dNTP、引物、Taq酶和模板5种因素5个水平上对甜菜RAPD反应体系进行优化,确立了适合甜菜RAPD反应体系:25μL反应体系中含1×Buffer、1.0 mmol/LMg~(2+)、1U Taq DNA聚合酶、0.25 mmol/LdNTP、0.4μmol/L随机引物和25 ngDNA模板。利用优化的RAPD反应体系对38个甜菜品种进行亲缘关系分析。结果表明,38个品种之间的多态性比较高,变异大。聚类图结果表明,38个甜菜品种遗传距离的变异范围在0.14～0.72。当以遗传距离0.50来划分时,可将38个品种分为两大类,以遗传距离0.40来划分时,又可以把第2大类分为6个亚类。结果显示,RAPD优化体系适合甜菜亲缘关系鉴定。     

高温胁迫对岷江百合幼苗耐热指数和理化特性的影响

为了探明岷江百合幼苗在高温胁迫下的生理反应,以离体扩繁的岷江百合幼苗为研究材料,对其进行了不同高温(37℃/30℃、42℃/37℃)和不同时间(0、4、8、16、32、48 h)处理,研究了高温胁迫对其耐热指数和有关生理生化指标(叶绿素、丙二醛、游离脯氨酸、可溶性蛋白含量和SOD活性)的影响.结果表明:随着温度的升高和处理时间的延长,植株的耐热指数不断下降,叶绿素含量减少,丙二醛(MDA)含量增加;42℃胁迫32 h后,游离脯氨酸、可溶性蛋白含量、SOD活性均达到最大值,分别比对照增加了0.66倍、1.77倍和9.78倍.但胁迫48 h后,指标显著下降,这说明,42℃间断胁迫48 h对植株产生了不可逆的的热伤害作用.     

8个大果樱桃品种特性比较及综合评价

[目的]筛选适合青海省规模发展的大果樱桃优良品种。[方法]通过对青海省主栽品种红灯、拉宾斯等品种进行抗性测定,综合各品种抗裂果、抗寒及果实品质,筛选适合青海省规模发展的优良品种。[结果]红灯为适合青海省栽培的早熟品种;拉宾斯、艳阳为适合青海省栽培的中晚熟品种。[结论]该研究可为青海省大果樱桃产业发展奠定理论基础。     

湖羊在西北寒旱地区行为学和生理指标的观测

为了研究西北寒冷干旱气候条件下湖羊的行为和生理指标变化,进而为西北地区湖羊引种提供数据支持和理论依据,本试验选用12只(公、母各半)舍饲周岁湖羊,通过近红外摄像技术研究了不同季节(A因子,A₁夏季,A₂冬季)、性别(B因子,B₁♂,B₂♀)和不同时段(C因子,C₁昼,C₂夜)条件下湖羊的采食、饮水、反刍、卧息等行为。结果表明,季节因子(A因子)对湖羊采食、卧息、反刍等行为均有极显著影响(P<0.01);性别因子(B因子)仅对湖羊采食和卧息行为有显著影响(P<0.05);昼夜因子(C因子)对湖羊的卧息行为有显著影响(P<0.05),对其采食和反刍行为有极显著影响(P<0.01)。季节和性别的交互作用对湖羊采食行为有显著影响(P<0.05),对反刍行为有极显著影响(P<0.01)。其余因子间交互作用对湖羊行为学无显著影响。试验羊体温、心跳、呼吸频率和血常规等生理指标均在正常范围内。以上结果说明湖羊在当地表现出了良好的适应性,在西北地区引种湖羊可行。     

氮素水平对芥蓝生长及芥子油苷含量的影响

采用溶液培养方法,研究了不同供氮水平对芥蓝生物量及抗癌次生代谢物芥子油苷含量的影响。结果表明,氮素水平从N100 mg/L到常规营养液的 N 200 mg/L范围内,芥蓝地上部、根部及菜苔鲜重均随供N水平的提高而显著增加,但菜苔总芥子油苷含量却随供N水平提高而显著降低;当N素水平提高到N 300~400 mg/L时,芥蓝生物量不再显著增加;而菜苔总芥子油苷含量相对于N 150和200 mg/L处理却显著增加。由于脂肪族和吲哚族芥子油苷分别来源于不同的氨基酸,两者的含量随供N水平的变化趋势不同。脂肪族芥子油苷含量以N 100 mg/L处理最高,是常规供N (200 mg/L)处理的1.2倍,吲哚族芥子油苷以400 mg/L处理最高,是常规供N处理的1.5倍。显然,在常规营养液的供N水平下,可以获得理想的芥蓝生物产量;但适当提高供N水平,在保证高产的同时可显著提高芥蓝菜苔的芥子油苷含量,有利于提高其抗癌品质。