双斑萤叶甲成虫的取食选择性研究

为综合治理双斑萤叶甲的危害,拓展新的防治途径,对双斑萤叶甲成虫的取食选择性进行研究。试验中,采用四臂嗅觉仪测定和田间试验方法研究,结果表明,在6个玉米品种中,双斑萤叶甲成虫对垦粘1号的选择性强,对庆单4和四单19的选择性弱,在供试的2种植物中,对紫花苜蓿的选择性强。总体表现为双斑萤叶甲成虫对紫花苜蓿的选择性强,垦粘1号次之,庆单4和四单19弱。     

皱纹盘鲍成体摄食习性的初步研究

本文介绍了皱纹盘鲍(Haliotis discus hannai Ino．)摄食习性的试验情况。试验结果表明，皱纹盘鲍的日摄食量周年在春末夏初和秋季有两个高峰期；当水温高于24℃或低于7℃时摄食量明显下降，低于3℃时基本上停止摄食。鲍对不同种类饵料有明显选择性，按其喜食程度排列为裙带菜、巨藻、海带、礁膜、石莼，而石花菜、海蒿子、鼠尾藻的摄食量最小；而且对同种藻类喜食嫩的，少食甚至不食老的藻体。不同大小个体的日摄食率不同，小个体的摄食率较大个体为高，而且在一年中坚持高日摄食率的时间也较长；最高日摄食率小个体鲍为13．6％，大个体为11．4％     

Variation of Color and Ray Pattern in Juvenile Shells in Hatchery‐produced Freshwater Triangle Pearl Mussels,Hyriopsis cumingii,in China

The variation and inheritance of juvenile shell color and pigmentation pattern in the freshwater mussel, Hyriopsis cumingii, were reported in 1‐yr‐old progeny of eight families. There were three distinctive phenotypes of shell color and pigmentation patterns observed, including a greenish‐brown shell with radial rays, yellowish‐brown shell with radial rays, and yellowish‐brown shell without radial rays. There were no greenish‐brown individuals without radial rays. The shell color phenotypes showed variation with the growth in juvenile Stage I (1–3 cm in shell length), and the percentage of individuals with radial rays increased once they reached a shell length of 11 mm and then stabilized after reaching 20 mm in shell length. Shell color differentiation became more apparent at a shell length of 26 mm. Results of chi‐square tests of the segregation ratio of shell color or ray phenotypes obtained from eight families at juvenile Stage II (6–9 cm in shell length) suggested that greenish‐brown is controlled by a dominant allele (G) and yellowish‐brown‐shell phenotype is by a recessive allele (y); the ray pattern phenotype is controlled by a recessive (r) and a dominant allele (R) at a single locus. Shell color phenotypes may be a useful genetic marker for future selective breeding of triangle pearl mussels.     

自然流水养鱼高产技术

自然流水养鱼是一种利用自然流水增加水中溶氧量,扩大放养量,增进鱼类生长速度的集约化养殖形式.具有小坑塘、全流水、高密度的特点.既可家庭养鱼形式,又可向工厂化养殖发展.     

Reproductive characteristics of <Emphasis Type="Italic">Gymnocypris firmispinatus</Emphasis> in the Anning River,China

The reproductive characteristics of Gymnocypris firmispinatus were determined from 582 individuals collected in the Anning River, China. The sex ratio (male: female) was 1:1 for the overall population but 3.1:1 for the mature group. Females reached a larger total length and total weight (242 mm and 148.17 g) than males (163 mm and 41.58 g). Lengths and ages at maturity were estimated to be 83.4 mm and 2.4 years for males, 130.7 mm and 5.9 years for females, respectively. Based on the analyses of gonad development and the size distribution of oocytes, G. firmispinatus spawned from March to May with high degree of the spawning synchronicity. The opposite tendency between gonado-somatic index and hepato-somatic index from January to March in females indicated that the energy requirement for the oocytes growth may be derived from the liver. In addition, the estimated mean fecundity and mean relative fecundity were 1227 and 29.7 eggs per g total weight. The fecundity of G. firmispinatus increased linearly with increasing of total length, total weight and ovary weight. This study provides details about the reproduction suggesting that G. firmispinatus might be especially vulnerable to exploitation in the Anning River.     

油松人工林养分循环的研究 Ⅱ.油松人工林养分元素的动态特性

本文以华北中山地区的油松人工林分作为研究对象,在林分各组分营养元素含量静态分布研究的基础上,对林分养分元素的动态特性进行了分析讨论,结果表明:(1)在一年中林木枝、叶、磷、钾、镁的含量因季节而异,其变化规律与林木的生长节律有关;(2)针叶凋落的年动态及其养分含量的变化,在一定程度上也受林木生长节律影响;(3)林地枯落物平均年干重损失率为14％,与其它林种相比,该立地上的油松林分林地枯落物分解较慢。     

贵阳烟区云烟87不同长相中棵烟产量和质量比较分析

为进一步提升烤后烟叶品质,为贵阳烟区提供理想中棵烟株型判别标准,以云烟87为试验材料,研究成熟期3种不同长相的中棵烟（T1：小,T2：中,T3：大）烤后烟叶产量和质量。结果显示,不同长相中棵烟烤后烟叶经济性状及烟叶品质差异显著,T2处理烟株的产量和质量最为协调,单位面积产值最高,达55188.15元/hm2,烤后上等烟比例达60.23%,较T1和T3处理分别提高了12.24%和8.59%;T2处理烟叶均价最高,为27.12元/kg,较T1和T3处理分别高出2.14和1.47元/kg;T2处理烟叶油分较多,色度较强,化学协调性优于其他2种株型中棵烟,感官质量总得分比T1和T3处理分别提高2.30和1.63分。综上所述,贵阳烟区理想中棵烟株型形态参数以株高109.30cm、茎围10.70cm、节距5.70cm、留叶数17.33、腰叶长73.97cm和腰叶宽32.43cm为宜。     

长三角地区典型季节规模化奶牛场氨排放特征研究

为掌握长三角地区规模化奶牛场氨排放特征,通过在线高分辨率监测系统对典型规模化奶牛场的棚舍养殖、粪便堆肥和污水贮存环节进行连续监测,获取不同环节、不同季节的氨排放信息,并计算得到本地化氨排放系数及排放强度。结果表明：规模化奶牛场棚舍养殖、粪便堆肥和污水贮存3个环节的年均氨排放浓度分别为（2.53±0.88）、（2.68±1.72）mg·m^-3和（2.44±1.73）mg·m^-3,氨浓度季节变化趋势总体表现为夏季>秋季>春季>冬季,夏季为冬季的2.3~4.2倍。不同环节氨排放小时变化存在明显差异,主要受日气象因子变化、畜禽活动和清粪管理等因素影响。温度是影响奶牛养殖氨排放水平的主要气象因素,与棚舍养殖、粪便堆肥和污水贮存3个环节的氨浓度水平均呈极显著正相关关系,相关系数分别达到0.914、0.817和0.942,而风速和大气压强则与各环节氨排放浓度呈负相关关系。基于在线监测获得了奶牛养殖氨排放本地化系数,棚舍养殖、粪便堆肥和污水贮存3个环节的年均氨排放系数分别为（13.14±5.17）、（7.71±5.17）kg·头^-1·a^-1和（9.72±4.47）kg·头^-1·a^-1,全年合计氨排放系数为30.57 kg·头^-1·a^-1。采用本地实测氨排放系数,建立了长三角地区规模化牛场氨排放清单,2018年长三角地区规模化牛场氨排放总量为3.39万t,氨排放主要集中在安徽省中北部和江苏省北部等集约化畜禽养殖规模较大的地区,夏季氨排放总量和强度最高,达到了1.36万t和151 t·d^-1,是冬季的3倍多。