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991.
Composted pig manure (CPM), unmixed or in mixture with perlite, was evaluated as growing medium based on both physical characteristics and agronomic performance. The physical properties were determined in CPM, perlite (0.5–2.5 mm), and their 75:25, 50:50 and 25:75 mixtures by volume. It was found that unmixed CPM has a higher bulk density (BD) than perlite, a slightly lower air space at a suction of 10 cm, and a markedly higher content in easily available water (EAW), although the water content at a suction of 10 cm is the same in the two media. Mixing CPM with perlite by 50:50 seems to increase the actual water content and decrease the actual air content at container capacity, while the BD and the EAW score intermediate to those in the unmixed constituents. Simulation of the relative hydraulic conductivity (Kr) indicates a sharp decrease in the unsaturated hydraulic conductivity (K) of CPM, perlite and their mixtures as the media suction increases. The differences in the decrease rate of Kr between the tested substrates are rather small, with the most and least steep decrease being observed in perlite and the mixture by 50:50, respectively. The agronomic performance of CPM was assessed by growing greenhouse cucumber in bags filled with perlite up to 20 cm in height, CPM up to 10 or 20 cm in height, and their mixture by 50:50 up to the same heights as CPM. A media height of 10 cm in the bag resulted in appreciably higher yields than a height of 20 cm, regardless of the type of the substrate, while the latter had no significant effect on yield. This effect of media height was ascribed to the steep decrease in K, which was minimized in all media at higher suction levels than 10 cm, thereby severely restricting water availability in their upper layers (10–20 cm) when their height in the bag was 20 cm.  相似文献   
992.
郑番06-10是以04商引常规-1-混-混为母本,以05早粉父本-混为父本配制的自封顶番茄一代杂种。幼果微具青果肩,成熟果亮粉红色,近圆形,平均单果质量153 g;田间表现对叶霉病、病毒病抗性与中杂9号相当;畸形果和裂果率为2.22 %,抗裂果;果实硬,耐贮运,整齐度高。可溶性固形物含量4.8 %,果肉VC含量294 mg?kg-1,总酸含量0.42 %,可溶性总糖含量2.58 %,品质佳。综合性状表现优良。产量6 400 kg?(667 m2)-1。适合河南、河北、陕西等地早春温室、拱棚、春露地及高山越夏种植。  相似文献   
993.
Selected wild Dahlia species in their natural habitats from west‐central Mexico were tested for the presence of three caulimoviruses known to be associated with cultivated dahlia (Dahlia variabilis), viz. Dahlia mosaic virus (DMV), DMV‐D10 and Dahlia common mosaic virus. Virus species‐specific primers and PCR were used followed by cloning and sequencing of the amplicons. Results showed that the wild dahlia species in their natural habitat contained DMV‐D10, which is an endogenous plant pararetrovirus. Viral sequences were found in 91% of the samples (n = 56) representing four different wild species. The gene coding for the movement protein of DMV‐D10 from Dahlia coccinea and all other species was cloned and sequenced. Sequence comparisons showed divergence of this gene when compared to that of DMV‐D10 from cultivated dahlias. The discovery of plant pararetroviruses in wild dahlia species in their natural habitats suggests a possible emergence, co‐existence and co‐evolution of pararetroviruses and their host plants.  相似文献   
994.
995.
土壤异养呼吸是影响土壤有机碳积累的关键因素。以南方红壤水土流失区不同恢复年限的马尾松林(未治理地(Y0)、恢复14 a(Y14)、恢复31 a(Y31))为对象,对不同呼吸组分进行测定并结合温度、水分以及微生物等因子,研究马尾松林恢复对土壤异养呼吸的影响。结果表明:不同恢复年限马尾松林土壤异养呼吸差异显著,恢复31 a显著大于恢复14 a以及未治理地,未治理地异养呼吸速率仅为0.99 μmol?m-2?s-1,而治理14 a、31 a分别为2.20、2.80 μmol?m-2?s-1;温度是异养呼吸季节变化的主要影响因子,分别解释季节变化的40.6%(Y0)、62.2%(Y14)、66.6%(Y31);马尾松林恢复后土壤异养呼吸温度敏感性(Q10)显著增加,Y0、Y14、Y31的 Q10分别为1.58、1.93和1.82;不同恢复年限土壤异养呼吸占土壤总呼吸比例为77.94%(Y0)、70.84%(Y14)、77.35%(Y31)。结构方程表明,在马尾松林恢复过程中,土壤有机碳(SOC)、温度以及土壤微生物多样性变化是影响土壤异养呼吸变化的主要因子,其中SOC、土壤微生物与异养呼吸显著正相关,而植被恢复过程中土壤温度变化与异养呼吸显著负相关。本研究结果表明,马尾松林植被恢复过程中SOC的积累以及缺乏有效的物理保护增加了微生物对SOC的分解,另一方面土壤环境温度的降低和细菌、真菌丰度的增加以及群落中变形菌、子囊菌、酸杆菌的增加,更进一步加剧微生物对原有土壤有机质的分解强度,导致异养呼吸碳排放的持续增加,最终限制了马尾松林土壤碳吸存效率。因此,较高的土壤异养呼吸可能是影响红壤侵蚀退化区土壤有机质进一步提升的关键。  相似文献   
996.
津优10号黄瓜以本所优良自交系81为母本,以荷兰黄瓜与中国黄瓜杂交后代经多代自交获得的自交系48为父本杂交而成.生长势强,第1雌花节位在第4节左右,前期以主蔓结瓜为主,早熟,坐瓜率高,瓜条顺直,亮绿色,中等刺瘤,瓜长36cm,横径3cm,单瓜质量160g,抗黄瓜霜霉病、白粉病、枯萎病能力强,适合春秋大棚栽培,每667m2可达5500kg,目前已在天津、河南、河北、山东、内蒙等地示范推广.  相似文献   
997.
胸腺是哺乳动物的中枢免疫器官。为了解猕猴胎儿中枢免疫器官在自然流产时的免疫应答情况,采用猕猴(Macaca mulatta)自然流产胎儿为材料,通过HE染色和免疫组化染色对不同胎龄猕猴胎儿胸腺白细胞介素2和10(IL-2;IL-10)阳性细胞的分布及表达进行观测,研究其在自然流产过程中的表达情况。结果表明:猕猴胎儿胸腺各胎龄组小叶间分界清晰,小叶数量皮质髓质中淋巴细胞数量也逐月增加;2月胚龄髓质形成,开始出现弥散型胸腺小体,3月胚龄髓质中可见典型胸腺小体,胸腺组织结构趋于完善。胸腺IL-2和IL-10的表达在1月龄无阳性,此后阳性细胞的光密度值和阳性细胞面积率随着月龄的增加而增长;阳性细胞分布于皮质边缘、皮质与髓质交界处、髓质中心区,以及没有退化的胸腺小体和血管周围;IL-2在胸腺中的表达强烈且数量多,IL-10表达较少。研究结果提示两种细胞因子主要在胸腺细胞发育增长活跃区域表达,并以IL-2表达为主,IL-2和IL-10的分泌水平可作为预测孕妇早产的一个新的敏感指标。  相似文献   
998.
Equine recurrent airway obstruction (RAO) is an inflammatory, obstructive airway disease induced by exposure of susceptible horses to inhaled organic dust particles. The immunological process underlying RAO is still unclear. Previous studies have shown that RAO is linked to the Interleukin-4 receptor (IL-4R) gene in one Warmblood family (F1), but not in another (F2). It has also been shown that in F1, but not in F2, RAO is associated with resistance against parasites, suggesting that this association may have an immuno-genetic basis. Therefore, we hypothesized that the T helper (h)1/Th2/regulatory (Treg) cytokine profiles of RAO-associated antigen- and parasite-antigen-stimulated peripheral blood mononuclear cells (PBMC) differ between RAO-affected and healthy horses depending on their genetic background. In our study, PBMC from 17 RAO-affected and 14 healthy control horses of F1 and F2 were stimulated for 24 h with antigens relevant to RAO [hay dust extract (HDE), Aspergillus fumigatus extract (AFE) and lipopolysaccharids (LPS)]; cyathostomin extract (CE) and recombinant cyathostomin antigen (RCA) or with concanavalin A (ConA). Total mRNA levels of IL-4, IL-4R, IL-13, interferon (INF)-γ and IL-10 were examined by qRT-PCR. Stimulation with either HDE or RCA resulted in significant differences in IL-4R mRNA levels between RAO-affected and control horses in F1, but not in F2. For IL-10 mRNA expression, a significant difference between RAO-affected and control horses in F1 but not in F2 was observed only following stimulation with HDE. In contrast to HDE, stimulation with CE resulted in a significant difference of IL-10 mRNA expression level between RAO-affected horses of F2 and healthy horses of F1. No significant differences were detected upon stimulation with any of the other challenge agents. These findings indicate that the immunological response, specifically IL-4R expression, in response to hay dust and cyathostomin antigens, differs between RAO-affected and healthy horses depending on their genetic background. This study shows that analysis of PBMC reveals systemic changes associated with RAO and helps to elucidate immunological pathways involved in this disease.  相似文献   
999.
不同经营措施对尾巨桉人工林土壤呼吸的影响   总被引:1,自引:0,他引:1  
以南宁七坡林场不同经营措施下的3年生尾巨桉林为研究对象,于2013年10月至2014年9月,采用Li 8100土壤碳通量系统测定土壤呼吸速率月变化,分析不同经营措施及土壤温度对土壤呼吸的影响。结果显示:尾巨桉林土壤呼吸速率具有明显的季节变化,峰值出现在2013年10月和2014年6月;不同经营措施间的土壤呼吸速率均存在显著差异 (P < 005),其大小排序为造林密度2m × 3m > 4m × 3m,施肥量08kg/株 > 06kg/株,除杂处理 > 未除杂;2013年10月至2014年9月土壤呼吸与土壤温度存在极显著的指数相关关系 (P < 001),土壤温度可以解释土壤呼吸速率变化的848%,Q10值为1610。  相似文献   
1000.
The thymus is a primary lymphoid organ where the primary T cell repertoire is generated. Thymus atrophy is induced by various conditions, including infectious diseases, glucocorticoid treatment, and poor breeding management. Cattle with thymus atrophy tend to exhibit weak calf syndrome, a condition in which approximately half of neonates die shortly after birth. Calves with thymus atrophy that survive the first month typically contract chronic inflammatory diseases. In this study, we analyzed the populations of the peripheral blood mononuclear cells and thymocytes in calves with thymus atrophy. In addition, we evaluated polarization of master gene and cytokine mRNA expression in peripheral blood CD4+ cells in the calves. The population of CD4+CD8+ cells in thymus of the calves with thymus atrophy was lower than that of control calves. IL10 mRNA expression in peripheral blood CD4+ cells of calves with thymus atrophy was significantly lower than that of control calves. TBX21 mRNA expression in peripheral CD4+ cells of thymus atrophy calves was tended to be higher than that of the control group. In addition, FOXP3 mRNA expression in peripheral CD4+ cells of the thymus atrophy calves was tended to be lower than that of the control calves. Thymus atrophy calves exhibited chronic inflammatory disease leading, in severe situations, to conditions such as pneumonia with caseous necrosis. These severe inflammatory responses likely are due to decreases in IL10 mRNA expression, impairing control of macrophages, one of the main cell fractions of natural immunity.  相似文献   
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