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101.
高淀粉、高产、多抗玉米杂交种正红115的选育研究   总被引:3,自引:4,他引:3  
以美国玉米带杂交种3163为基础材料,通过南北穿梭同步定向育种新方法,用自交系48-2作测验种在S1和S3早期分离世代连续进行早代测定和定向选育,同步育成玉米新自交系K169及其组配的杂交种正红115(K169×48-2)。正红115子粒粗淀粉含量高达75.7%,并具有综合品质优、产量高、抗病及抗倒伏力强、株型好和适应性广等特点。正红115适宜丘陵山区种植,具有广阔的推广应用及加工利用前景。  相似文献   
102.
天然橡胶价格的波动对我国经济发展以及橡胶产业安全有较大影响。采用灰色关联模型分析我国天然橡胶价格波动的影响因素,结果表明:各因素与天然橡胶市场价格的关联程度大小依次为:合成橡胶进口数量人均国民生产总值橡胶产量天然橡胶进口数量合成橡胶产量橡胶轮胎外胎产量。据此提出相关政策建议,以期为我国橡胶产业的长足发展提供参考。  相似文献   
103.
化学试剂对翅荚决明种子萌发和幼苗早期生长的影响   总被引:1,自引:0,他引:1  
为探讨不同化学试剂对翅荚决明(SennaalataL.)种子发芽率和幼苗生长的影响,用4种不同浓度的化学试剂(KNO3、GA3、KMnO4和NaOH)分别处理种子。结果表明:0.5~4.0g/LKMnO4和0.05~0.4g/LGA3浸种显著促进种子萌发,加快幼苗生长速度,其中以0.1g/LGA3和4g/LKMnO4浸种24h效果最佳,是解除翅荚决明种子休眠、促进幼苗生长的有效措施;1~8g/LKNO3浸种显著促进了种子萌发,但对幼苗生长影响不明显;而5~40g/LNaOH浸种明显抑制种子萌发和幼苗生长,且随着浓度增加,抑制作用明显增大。。  相似文献   
104.
马铃薯晚疫病流行学及防治方法研究进展   总被引:13,自引:3,他引:13  
马铃薯晚疫病流行性强,危害严重,是限制马铃薯生产的主要病害之一。针对目前生产上该病害防治困难的现状,本文综述了马铃薯晚疫病流行学和防治方法的研究进展,并对今后的研究提出了建议。  相似文献   
105.
杨晖  赵鹂  张龙  梁巧玲  柯乐芹 《核农学报》2015,29(1):183-191
香菇等可食用菇类比绿色植物体内更能逐步聚集浓度大的镉等重金属。子实体中的镉危及食用者的健康,因此减少菇类子实体中镉的含量,对人体健康意义重大。本研究检测了5种外源添加物水杨酸、沸石、石膏、壳聚糖及硫酸锌对镉胁迫下香菇体内镉含量的降低作用,并测定不同添加物对香菇羧甲基纤维素酶和漆酶活性的影响。试验结果表明,被测试的添加物中,硫酸锌对香菇808和868子实体中的镉含量著,石膏次之,表明硫酸锌是5种外源添加物中降低香菇体内镉浓度的最佳选择。此外,通过测定5种外源添加物在3 mg·kg-1镉胁迫下对香菇羧甲基纤维素酶和漆酶活性的影响,试验数据表明菌丝满袋期时,在添加硫酸锌或石膏时,香菇羧甲基纤维素酶和漆酶活性达到最高,说明培养料中添加硫酸锌或石膏在降低香菇体内镉含量的同时,也可以一定程度上增强生长代谢酶的活性。  相似文献   
106.
近年来,安庆市宜秀区大力实施“产业富民”发展战略,充分发挥区位优势和资源优势,为现代农业的发展奠定了坚实的基础.该研究基于现代农业的内涵,分析了宜秀区现代农业发展的现状及存在的问题,提出了宜秀区现代农业发展的思路与对策,以实现农业发展、农村繁荣、农民增收的目标,打造“宜游宜秀”.  相似文献   
107.
【目的】研究叶面施肥对热带设施甜瓜产量及品质影响,探讨甜瓜有机水溶肥叶面施肥的应用效果,为热带设施甜瓜叶面肥的推广提供理论与实践依据。【方法】设计肥料浓度4种水平组合,以清水为对照,研究有机水溶肥料不同浓度对热带设施栽培甜瓜生长发育、产量和品质的影响。【结果】喷施有机水溶肥料的处理各次观测的叶片面积较对照高16.56%、18.36%和7.38%。叶片SPAD值平均较对照分别提高了13.75%、14.98%和13.70%。甜瓜纵横径增加,纵径分别提高6.75%、14.53%、15.88%和16.65%,横径分别提高3.28%、7.12%、9.33%和9.47%。随着用量的增加,产量也呈增加趋势,增产比例分别为9.01%、26.44%、28.50%、31.02%。【结论】不同浓度水溶肥料叶面喷施对热带设施甜瓜产量和品质有明显影响,采用伸蔓期200 ml/(667 m2·次),其它时期250 ml/(667 m2·次)的喷施方法可显著提高产量,提升品质。  相似文献   
108.
回顾了中国证券市场理论估值的研究,发现用平均市盈率进行国际比较对股票市场估值有较大缺陷.认为一个国家股票市场的理论价值定位必须考虑一国的利率、经济增长率、国家风险等.本文运用两元增长模型加入国家风险对中国股票市场进行理论估值探讨,认为中国股票市场目前的估值合理,具备投资价值.  相似文献   
109.
The immunogenicity of the ts-11 vaccine strain of Mycoplasma gallisepticum was assessed following eye drop or coarse aerosol administration in chickens of various ages. Protection was evalualted following intra-abdominal (IA) or fine droplet aerosol administration of virulent M. gallisepticum, usually the Ap3AS strain and was measured mainly by the scoring of gross air sac lesions or by egg production. Vaccination of chickens with ts-11 did not elicit a substantial serum antibody response as measured by rapid serum agglutination test, or ELISA. Protection was never demonstrated when no M. gallisepticum serum antibody response was detected in a vaccinated group of chickens. Failure to protect occurred usually, although not invariably, following aerosol administration of the vaccine. Vaccination by eye drop usually, although not invariably provided protection against challenge. In one experiment, chickens vaccinated by eye drop at 8-weeks were as susceptible as non vaccinated controls when challenged by IA inoculation at 13-weeks-of-age. Yet other birds from the same vaccinated group were resistant when challenged in an identical way at 23-weeks. No measurable increase in M. gallisepticum specific serum antibody concentrations occurred in the intervening period. Equally surprising was the response of another group of birds in the same experiment that had been vaccinated with a higher dose of ts-11. An antibody response was detected in this group, but they were susceptible to challenge at 23-weeks. Interestingly, a drop in egg production commenced 4 weeks after challenge, 2 weeks later than that observed in a non vaccinated group challenged at the same time.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
110.
SUMMARY The presence of abnormal T waves in three or more electrocardiographic leads has been used to diagnose the cause of poor race performance in horses. This study investigated the relationship between previous racing performance in Standardbred horses and T waves, and the effect of training on the T wave. Thirty-two horses were electrocardiographed in two Sydney racing stables. Sixteen horses (50%) had ECGs with three or more leads with abnormal T waves, and these horses had won more races, had a greater ratio of wins per start and a greater number of dollars earned per start than horses with less than three abnormal T waves (P < 0.05). Horses with abnormal T waves also had significantly faster racing times (P < 0.01). There were significant (P < 0.01) correlations between the number of abnormal T waves and both number of wins (R = 0.47) and dollars earned per start (R = 0.45). Fastest winning mile rate was also negatively correlated with number of leads with abnormal T waves (R =?0.52, P < 0.01). Twenty two horses were also electrocardiographed within seven days of good racing performance. The mean number of abnormal T waves was 2.7 ± 0.41, and the mean T wave amplitude in the four chest leads (CV, CR, CL, CF) was 0.9 ± 0.15 mV. Thirteen horses (59%) had abnormal T waves in three or more leads. The effect of training on the T wave was also investigated in nine previously untrained and unraced Standardbred racehorses. There were significant effects of training (P < 0.01) on the number of abnormal T waves and mean chest lead T wave amplitude. These increases occurred in the second phase of training during which faster exercise, race trials and racing were conducted. We concluded that abnormal T waves are a common finding in the race-fit Standardbred horse, and can be found in more than 50% of horses currently performing well in races. In addition, chest lead T waves become more positive after training.  相似文献   
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