黄粉虫种内杂交初步研究

通过黄粉虫黄色品系(Y)和黑色品系(B)间杂交试验,对其杂种1代产卵量、个体大小、头宽及蛋白质含量等方面进行了研究和探讨。结果表明:杂交组合B♀×Y♂在产卵量、头宽、蛹重等方面较两个自交组合达到了显著或极显著水平。其中产卵量较自交组合B♀×B♂相比提高116.83%;而杂交组合Y♀×B♂的卵长、卵重、产卵量、幼虫头宽、幼虫体重、蛹重、蛋白质含量、耐高温能力与Y♀×Y♂、B♀×B♂相比均达到显著或极显著水平,其中蛋白质含量较自交组合B♀×B♂相比提高21.05%。     

杨干象对杨树生长的影响和防治指标的研究

1995～2000年，对杨干象对杨树生长的影响和防治指标进行了研究。结果认为，不同虫口密度对杨树生长的影响明显，通过建立虫口密度与杨树生长(树高、胸径、材积)损失率回归预测模型表明，随着虫口密度的增加，胸径、材积生长明显下降，其关系呈直线、对数回归关系；高生长总的趋势是下降的，呈多项式回归关系；杨干象防治指标确定为：5年生以下杨树为2头／株，6～8年生杨树为3头／株，9年生以上杨树为4头／株。     

夏直播花生规范化栽培密度与氮肥优化配置研究

采用二次饱和D—最优设计建立了密度和N肥用量与夏直播花生产量的数学模型。进一步分析表明，密度与N肥用量呈负交互效应，肥料用量增加，花生密度可适当减少。密度与N肥用量的最优组合为每公顷播15．36万穴，施纯N99．6kg，最高产量可达到5527．0kg。公顷产量在4500~5527kg范围内的措施组合为：每公顷播15．O～18．7万穴，施纯N65．1～124．4kg。     

苎麻属野生种的光反应类型研究

对苎麻属11个野生种资源进行了10h、13h、16h光照处理，在不同光长条件下，表现出短光照生育期缩短、长光照生育期延长；短光照生育期延长、长光照生育期缩短；长、短光照生育期都延长；长、短光照生育期都缩短四个类型，并且不同光照时间对不同的生殖生长期有不同的影响，生长发育的积温差异较大。     

羊生长激素的提取及生物化学和生物活性的测定

600 g 冰冻羊垂体经过酸性溶液提取、硫酸铵的分级分离和 DEAE-纤维素柱层析得纯品(1),其得率为0.08g/kg,最后将部分纯品(1)过 Sephadex G-100分子筛,得到高纯的羊生长激素[纯品(2)]。提取的羊生长激素具有相当高的理化均一性,纯品(2):聚丙烯酰胺凝胶电泳呈现一条主带和二条酸性小带;聚丙烯酰胺等电聚焦电泳呈现二条带,其等电点分别为 pH7.35和 pH7.40,SDS—电泳呈现二条很难分开的带,其平均分子量为20 100道尔顿;用DNS-CI 法测得的 N-末端氨基酸是2个,丙氨酸和苯氨酸。纯品(1)理化均一性稍差:SDS—电泳较纯品(2)多出两条分子量低的带;等电聚焦电泳多出六条酸性小带。除此之外,其他理化性质同纯品(2)。用大白鼠胫骨实验测定生物活性,测得纯品(1)可使垂体大白鼠胫骨软骨盘的宽度相对增加79%。未对纯品(2)进行生物活性测定。用羊催乳素放射免疫药盒测定,纯品(1)和纯品(2)与羊催乳素均无交叉反应。     

光棘豆单细胞培养再生植株

由光棘豆种子无菌苗的胚轴和子叶诱导的愈伤组织建立起细胞悬浮系。由悬浮系分离出单细胞。单细胞在含有1～2mg/L 2,4—D的2/3MS培养基中采用振荡和静止两种方法培养。结果表明。振荡培养愈伤组织再生频率较高,所需时间较短。单细胞再生的愈伤组织转入分化培养基后分化出芽。幼苗转入含有IBA和IAA的1/2MS培养基中生根,成为完整的再生植株。在分化培养基中,只有瘤状愈伤组织能够分化出芽。并且较高浓度的细胞分裂素(6—BA或KT)或6—BA与ZT结合使用对愈伤组织的分化是有利的。     

An Epidemiologic and Economic Study of Respiratory Diseases in Two Conventional Danish Swine Herds. I: Prevalence of Respiratory Lesions at Slaughter and Their Effects on Growth

A total of 578 slaughter pigs from 2 Danish conventional farrow-to-finish operations (Herds A and B) were followed from an age of 14 days to slaughter. Pigs were weighed at 3 weeks intervals and at slaughter and an extended post mortem examination of the plucks was done. Comparison of growth rates in pigs with and without specific types of lesions by the t-test and those with multiple lesions with regression models demonstrated that Mycoplasma-like pneumonia, complicated pneumonia, anterio-ventral pleuritis, fissures and atrophic rhinitis significantly reduced mean daily gain and increased the time required to reach slaughter weight. The total impact of the lesions in Herd A was an estimated reduction in mean daily gain of 27 grams and a 2 day increase in the interval from 14 days of age until slaughter (MDG14). Decreases in MDG14 in Herd B were more substantial, 98 grams and 16.7 days. Reductions in mean daily gains during the interval from the fourth weighing until slaughter were 31 grams in Herd A and 137 grams in Herd B. Chronic dorso-caudal and parietal pleuritis, without other lesions present, had no significant adverse effects on growth rates in either herd. Interactions between lesions did not significantly alter the estimates. The R² values obtained for the regression models showed that the presence, absence or extent of lesions at slaughter explained only 13-27% of the variations in growth rates in the 2 herds.     

苜蓿施用污泥效果的研究Ⅰ对苜蓿生长及元素含量的影响

将兰州市七里河污水处理厂生活污泥施用于人工种植的新疆大叶苜蓿草地，探讨了不同施用量对苜蓿生长及各元素含量的影响。研究结果表明，施用1.0-2.0kg/m^2污泥，苜蓿地上生物量显著增加，第一年增产23％－31％，第二年增产15％－31％。施用污泥苜蓿地上和地下部组织中N，P，Ca,Mg和Mn的含量总体呈增加趋势，Fe含量显著增加，而K和重金属元素Ni、Pb、As和Hg的含量与对照无显著差异，Zn和Cu的积累增多，但地上部组织中重金属元素均未超过植物中的平均含量，施用污泥未对新疆大叶苜蓿造成重金属污染。     

黑龙江省植物物种及其保护概况

黑龙江省共有三个植物区,植物区系成分比较复杂,有多种多样的生态系统,植物物种非常丰富。目前,黑龙江省共有维管束植物185科92属2503种,种类较多的科依次是:菊科(Compositae)、禾本科(Gramineae)、莎草科(Cyperaceae)、蔷薇科(Rosaceae)等。但由于生境的破坏,我们黑龙江省每年都有一定数量的植物灭绝或处于灭绝的边缘,这要求我们对它们加以保护,主要方法有:就地保护、迁地保护等,不但对物种进行保护,更重要的是保护其生态系统。     

In vitro Plant Regeneration from the Mature Tissue of Navel Orange (Citrus sinensis L. Osbeck) by Direct Organogenesis

An efficient in vitro regeneration system by direct organogenesis from mature nodal and internodal stem segments of Newhall navel orange (Citrus sinensis L. Osbeck) was developed. Illuminating conditions together with plant growth regulators affected the adventitious bud regeneration frequency and efficiency. The initial 15 d darkness inoculation is beneficial for the adventitious bud regeneration. The highest regeneration frequency (85.2%) and bud formation efficiency (3.7 per responsive internodal stem segment) were obtained in the media supplemented with 1.0 mg L-1 BAP and 0.5 mg L-1 NAA. ABA at 0.2 mg L-1 positively affected the bud formation efficiency, which amounted to 8.5 buds per internodal segment in the presence of BAP at 1.0 mg L-1. The adventitious shoots successfully rooted and were transferred to the soil.