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71.
温度胁迫对柱花草叶绿素荧光参数和光合速率的影响 总被引:3,自引:1,他引:3
为了探讨柱花草对不同温度的适应机制,以播种后40 d的幼苗为试验材料,在光照培养箱内分别用高温(36℃)处理5 d,低温(6℃)处理2 d,并以常温(25℃)处理5 d为对照,测定光合速率及叶绿素荧光参数等相关指标在不同温度胁迫下的变化。结果表明,低温处理2 d,叶绿素荧光参数的最大光化学效率(Fv/Fm)、光系统Ⅱ电子传递量子效率(ФPSⅡ)、光化学猝灭系数(qP) 和非光化学猝灭系数(NPQ)、叶片光合速率、叶片ATP含量及RuBPcase和FBPase活性显著降低;而高温处理5 d对其光合效率没有产生明显的抑制作用。在温度胁迫条件下,足够的ATP供应对保证柱花草的光合能力是有必要的。 相似文献
72.
盐胁迫和干旱胁迫对蓝花子种子萌发和幼苗生长的影响 总被引:1,自引:0,他引:1
将蓝花子培养在含有不同浓度的NaCl和甘露醇的MS培养基上,研究蓝花子在不同浓度的NaCl和甘露醇处理下的发芽势、发芽率、相对发芽率、叶绿素含量以及过氧化物酶活性等,揭示蓝花子对盐胁迫和干旱胁迫的耐受能力。结果表明:蓝花子的发芽率、株高、根长、叶绿素以及过氧化物酶活性都随NaCl浓度的升高而显著下降;在甘露醇胁迫时,蓝花子幼苗的根长、叶绿素含量以及POD酶活性都随甘露醇浓度的升高表现为先升高后降低的趋势。说明同十字花科其它植物相比蓝花子对盐胁迫十分敏感,而对干旱胁迫却能表现出比较明显的耐受性。 相似文献
73.
西瓜未授粉子房的离体培养 总被引:1,自引:0,他引:1
为了探讨西瓜未授粉子房诱导率的影响因素,以‘早春红玉’、‘西农9号’和‘小绿皇’为供试材料进行西瓜未授粉子房的离体培养,研究供体植株的黑暗热激处理、基因型、不同取样时间、2,4-D浓度和不同激素浓度组合等因素对其芽点诱导率的影响。结果表明:西瓜未授粉子房离体培养以33℃的条件下黑暗热激4 d效果最佳;以开花前1 d的子房诱导率最高为17.2%;3个品种中仅‘早春红玉’获得了再生植株,且在激素组合为4.0 mg·L-12,4-D+2.0 mg·L-16-BA+0.5 mg·L-1NAA时芽点率最高为15.0%;根据再生植株的根尖染色体数目,初步鉴定再生植株中有单倍体植株,还有二倍体和四倍体植株。 相似文献
74.
猪乳中一组高分子量蛋白的多态性及其与繁殖性能关系的研究 总被引:9,自引:1,他引:9
采用十二烷基硫酸钠 聚丙烯酰胺凝胶不连续垂直板电泳 (SDS PAGE)对 16 2头二花脸母猪乳中一组高分子量蛋白质 (HMWP)进行了检测 ,计算了该位点的基因型频率、等位基因频率和遗传多样性指数等 ,并运用线性模型统计方法分析了该位点的不同基因型与母猪繁殖性能的关系。结果表明 ,在二花脸猪种群 ,乳中HMWP存在B(M :11480 0± 40 0 )和D(M :10 140 0± 6 0 0 )两种带 ,分别受二个等位基因HB 和HD 控制。BB、BD和DD三种基因型频率分别为 0 6 6 6 7、0 2 716和 0 0 6 17,两个等位基因HB 和HD 频率分别为 0 80 2 5和 0 1975 ,遗传多样性指数为0 3170。在三种HMWP基因型中 ,不同基因型母猪的繁殖性能在活仔数和窝重上存在着显著差异 (P <0 0 5 ) ,但在初生仔猪个体重和 2 0日龄窝重上未达到显著水平 (P >0 0 5 )。 相似文献
75.
将 40只 48周龄的蛋鸡随机分成 4组 ,分别饲喂用 5 %、10 %、2 0 %的马铃薯替代玉米的日粮。结果表明 ,饲喂 10 %马铃薯替代玉米的日粮 ,其代谢能和钙表观利用率与其他组差异不显著 (P >0 0 5 ) ,蛋白质和磷表观利用率都高于其它各组 (P <0 0 1)。 相似文献
76.
Background
Training of young Thoroughbred horses must balance development of cardiopulmonary function and aerobic capacity with loading of the musculoskeletal system that can potentially cause structural damage and/or lameness. High-speed equine treadmills are sometimes used to supplement exercise on a track in the training of young Thoroughbreds because the horse can run at high speeds but without the added weight of a rider. We tested the hypothesis that intermittent high-intensity exercise on a treadmill of young Thoroughbred horses entering training can enhance development of aerobic capacity (Vo2max) and running performance more than conventional training under saddle, and do so without causing lameness.Results
Twelve yearling Thoroughbreds trained for 8 months with conventional riding (C) only, conventional riding plus a short (2 month, S) interval of once-per-week high-intensity treadmill exercise, or a long (8 month, L) interval of once-per-week high-intensity treadmill exercise. Three treadmill exercise tests evaluated Vo2max, oxygen transport and running performance variables in June of the yearling year (only for L), October of the yearling year and April of the 2-year-old year. No horses experienced lameness during the study. Aerobic capacity increased in all groups after training. In both October and April, Vo2max in L was higher than in C, but did not differ between L and S or S and C. Running speeds eliciting Vo2max also increased in all groups after training, with S (809 ± 3 m/s) and L (804 ± 9 m/s) higher than C (764 ± 27 m/s). Maximum heart rate decreased for all groups after training. Hematocrit and hemoglobin concentration increased for L throughout training.Conclusions
Young Thoroughbred horses can increase aerobic capacity and running performance more than by strictly using track training under saddle with the addition of intermittent high-intensity treadmill exercise, and they can do so without experiencing lameness. This finding suggests that young racehorses might be able to achieve higher aerobic fitness during training without subjecting their musculoskeletal systems to increased loading and risk of developing lameness. The findings of this preliminary study do not indicate a specific protocol to best achieve this goal. 相似文献77.
78.
为了统计和研究石河子垦区大中型奶牛场临床型乳房炎的发病规律及治疗情况,选择石河子垦区6个大中型奶牛场2 600头奶牛作为调查对象,通过对临床型乳房炎进行鉴定及不同治疗方法进行比较。结果表明2 600头奶牛在4—9月份临床型乳房炎发病270头,发病率10.38%;10—3月份发病163头,发病率6.99%。目前在石河子垦区大中型牛场一般常见的治疗药物主要有左旋咪唑拌料、青霉素钾或先锋Ⅴ等+糖皮质激素、中草药组方和青霉素钾或先锋Ⅴ等+中草药组方等。结果,经过预防和治疗后,在4—9月份奶牛临床型乳房炎发病率降至4.92%;10—3月份奶牛临床型乳房炎发病率降至3.00%。调查结果表明:中西医结合用药对临床型乳房炎起到了积极的治疗作用。 相似文献
79.
Sayin F Dinçer S Karaer Z Cakmak A Inci A Yukari BA Eren H Vatansever Z Nalbantoglu S 《Tropical animal health and production》2003,35(6):521-539
An epidemiological survey for Theileria annulata infection was conducted in 12 selected villages around Ankara in Central Anatolia, Turkey, during the period April 1990 to January 1993. During the survey, 198 cattle of 30 local breeds, 84 Holstein-Friesian×local breeds and 84 Holstein-Friesian breed were examined for antibodies to T. annulata and the presence of the vector ticks. Four species of Hyalomma ticks were identified: Hyalomma anatolicum anatolicum, Hyalomma anatolicum excavtum, Hyalomma detritum and Hyalomma marginatum marginatum. Salivary gland staining indicated that infected adult ticks of all four species were present and, therefore, were implicated in the transmission of tropical theileriosis in the field. Generally, the Hyalomma infestation rate was low, with the heaviest infestations occurring on the older animals. Young adults and calves had very low infestation rates. Most ticks seen on cattle were adults, very few nymphs were found. The blood smear and serological examination of the 198 cattle conducted in March, before the start of the first disease season, showed that the prevalence of piroplasmosis was 11.1% (22 out of 198) and the seroprevalence of T. annulata was 10.6% (21 out of 198). Forty-three animals were then excluded from the study because they were seropositive and/or harboured piroplasms. Ninety-two seronegative animals showed piroplasmosis (92 out of 155) and 34 seronegative animals became seropositive for T. annulata (34 out of 155) during the three disease seasons. One animal became clinically ill with tropical theileriosis and required treatment. The incidence of cattle showing piroplasmosis and disease in the total study sample was 50.7% and 0.5% per disease season, respectively. The seroconversion rate of new infection with T. annulata in the total study was 14.3% per animal season. The number of cattle showing piroplasmosis was much greater than the number of seropositive cattle, which may indicate the presence of another species of Theileria. The two different management systems encountered in the study were considered to have influenced the tick infestation levels. 相似文献
80.