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101.
两种密度条件下玉米穗上节间距QTL分析   总被引:1,自引:1,他引:0  
为研究高密度胁迫下穗上节间距的遗传机制,以豫82×沈137的重组近交系(RIL)群体为材料,构建一张包含有1 114个位点的SNP标记的遗传连锁图谱,图谱总长度为1 821.79 cM,标记平均间距为1.64 cM。利用复合区间作图法在60 000株/hm~2密度下共检测到11个、120 000株/hm~2密度下检测到12个穗上节间距的QTL,位于第6染色体上的QTLq For ILL6-2/qForILG6在两种密度下同时被检测到,表明该QTL均能稳定表达;位于第9染色体上的qThiILL9/qForILL9-1在60 000株/hm~2的密度下同时被检测到,解释穗上节间距遗传变异的8.67%和10.61%,在120 000株/hm~2密度下未被检测到,表明此QTL在低密度下特异表达调控穗上节间距3、4。在高密度下检测到qSixILG6和qSixILG10分别解释穗上节间距6遗传变异的16.97%和13.66%,说明该QTL在高密度环境下特异表达。  相似文献   
102.
在对引江济淮规划区的概况、现状水质、现状污染源进行调查的基础上,进行了规划年2020年污染源预测。根据调水线路水质目标,选用合适的模型,以流域为单元,断面水质达标为目标,计算了引江济淮规划区各流域的纳污容量。在此基础上,制订了区域内的污染物总量控制方案,提出合理的水环境保护措施,确保引江济淮污染物削减目标可达,水质安全。  相似文献   
103.
采用水培方法,研究了不同钙离子浓度对蕹菜产量及生理生化的影响.结果表明:随着钙离子浓度的增加,蕹菜产量相应增加,当超过蕹菜生长所需的临界值时,其产量随着钙离子浓度的增加反而降低,钙离子浓度为80mg/L时,黑子蕹产量最高,达197.47 g.随着钙离子浓度的增加,3个品种蕹菜中超氧化物歧化酶活性和过氧化氢酶的活性都呈现先升高后下降的趋势,在0~80 mg/L钙离子范围内,2种酶活性随着钙离子浓度的增加而升高,在80~200 mg/L范围内,2种酶活性都随着钙离子浓度的增加而降低.相同钙离子浓度处理,3个品种中黑子蕹的净光合速率最高.  相似文献   
104.
天目山皆伐毛竹林自然更新群落类型与多样性分析   总被引:2,自引:2,他引:0       下载免费PDF全文
  目的  毛竹Phyllostachys edulis林是中国亚热带区域近30 a来不断扩展的森林群落类型之一,物种多样性单一、生态功能不强。近年来,毛竹林蔓延和入侵越来越严重,已威胁到竹林周边植被,势必要进行更新改造。本研究旨在探讨毛竹纯林皆伐后自然更新形成群落类型、生物多样性特点和影响因素。  方法  基于天目山毛竹林皆伐自然更新后形成的次生群落的监测数据,利用TWINSPAN分析方法对自然更新群落进行了分类,比较了不同群落之间α多样性之间的差异性,用冗余分析法分析环境因素的影响。  结果  毛竹林皆伐后自然更新群落物种和类型多样,可分成11个不同的群落,不同群落之间α多样性存在显著差异。冗余分析发现:在海拔、坡向、坡度3个地形因子中海拔是决定自然更新群落木本层以及草本层α多样性大小的主要因子,且与其呈显著负相关关系(P<0.05)。  结论  揭示了毛竹林皆伐后演替初期群落与环境因子的分布格局,为天目山自然保护区内植被恢复提供理论依据。图3表3参38  相似文献   
105.

Background

Survival times and tumor responses associated with malignant neoplasia of the lower urinary tract are poor despite the vast array of current treatments. Therefore, the evaluation of alternative treatments, such as intraarterial administration of chemotherapy (IAC) should be considered.

Objective

To describe a technique for superselective catheterization for IAC and to evaluate initial tumor response by ultrasonography after both IAC and intravenous administration of chemotherapy (IVC).

Animals

Client‐owned dogs with lower urinary tract neoplasia treated with either IVC (n = 15) or IAC (n = 11).

Methods

Retrospective study. An arterial approach via the carotid or femoral artery was utilized to obtain superselective access and administer chemotherapy in the IAC cases. Medical record review was performed, data were recorded, and recorded variables were evaluated statistically.

Results

Intraarterial chemotherapy was successfully administered in all cases. There was a significantly greater decrease in longest unidimensional measurement in the IAC group as compared to the IVC group (P = .013). The IAC group was also significantly more likely to have a tumor response as assessed by modified RECIST guidelines (P = .049). Dogs in the IAC group were significantly less likely to develop anemia (P = .001), lethargy (P = .010) and anorexia (P = .024).

Conclusion and Clinical Importance

This study demonstrated the feasibility and efficacy of performing IAC for lower urinary tract neoplasia. Further investigation is necessary as the follow‐up time was short and the impact on long‐term outcome and survival was not determined.  相似文献   
106.
玉米秸秆热值性状杂种优势及配合力分析   总被引:3,自引:0,他引:3  
采用NCⅡ交配设计以13个玉米亲本自交系组配42个杂交组合,对其玉米秸秆热值性状的杂种优势及配合力进行分析。结果表明,热值、纤维素含量、和木质素含量3个指标性状表现出明显杂种优势,热值杂种优势与纤维素含量、木质素含量的杂种优势关系密切,但不受半纤维素含量杂种优势的影响。一般配合力方差和特殊配合力方差均达到1%的极显著水平,说明不同自交系间存在较大的遗传差异。X178、掖52106的热值、纤维素含量、木质素含量的一般配合力较大,而半纤维素含量一般配合力较低;沈137的热值、木质素含量的一般配合力较高,纤维素含量的一般配合力居中,半纤维素含量的一般配合力低;这3个亲本在培育高热值玉米杂交种上具有较大应用潜力。沈137×黄C、齐319×昌7-2在热值、木质素含量、纤维素含量等性状上具有较高的特殊配合力,产生较强的杂种优势。笔者认为,玉米秸秆热值可作为玉米育种的目标之一,改变只注重产量和品质育种的做法,选育和推广既高产、优质,又高热值的玉米杂交种,提高玉米综合经济效益。  相似文献   
107.
Mammary neoplasms are the most common neoplasm in female dogs. This article describes the embryologic development, normal anatomy, and histology of the canine mammary gland from the onset of first estrous and the changes that occur in the mammary gland during the estrus cycle. The clinical features of canine mammary gland tumors and their relation to prognosis are discussed, including age, hormones, breed, diet, and obesity. Additional clinical prognostic factors including clinical presentation, tumor size, and lymph node status at the time of presentation are discussed in relation to diagnosis and tumor staging. Immunohistochemical evaluation of the cell differentiation markers of the normal and neoplastic canine mammary gland is described and compared with similar studies in humans; the ways these markers may be used to assist with the prognosis of canine mammary neoplasms are discussed.  相似文献   
108.
Indolent lymphoma comprises up to 29% of all canine lymphoma; however, limited information exists regarding the subtypes and biological behaviour. This retrospective study describes the clinical characteristics, histopathological and immunohistochemical features, treatment, outcome and prognostic factors for 75 dogs with indolent lymphoma. WHO histopathological classification and immunohistochemistry (IHC) for CD79a, CD3, Ki67 and P‐glycoprotein (P‐gp) was performed. The most common histopathological subtype was T‐zone, 61.7%, (MST 33.5 months), followed by marginal zone, 25%, (MST 21.2 months), P = 0.542. The addition of IHC to preliminary histopathological classification resulted in a revised diagnosis in 20.4% of cases. The use of systemic treatment did not influence survival, P = 0.065. Dogs treated with chlorambucil and prednisone did not reach a MST, compared with a MST of 21.6 months with CHOP‐based chemotherapy, P = 0.057. The overall MST of 4.4 years confirms that this is indeed an indolent disease. However, the effect of systemic treatment must be determined through prospective trials.  相似文献   
109.
The National Consensus Group recommends that all women with tumors larger than 1 cm be offered chemotherapy regardless of tumor histology of lymph node status. This recommendation is to ensure that everyone at risk for failing, even though the risk may be low in women with relatively small tumors and favorable histology, has a choice and receives the benefit of adjuvant chemotherapy. This type of treatment recommendation may also be made in dogs based on recognized, well-accepted prognostic factors such as tumor size, stage, type, and histologic differentiation. Based on the limited clinical information available in veterinary medicine, the drugs that are effective in human breast cancer, such as cyclophosphamide, 5-fluorouracil, and doxorubicin, may also have a role in the treatment of malignant mammary gland tumors in dogs. Randomized prospective studies are needed, however, to evaluate the efficacy of chemotherapy in dogs with high-risk mammary gland tumors and to determine which drugs and protocols are the most efficacious. Until such studies are performed, the treatment of canine mammary gland tumors will be based on the individual oncologist's understanding of tumor biology, experience, interpretation of the available studies, and a little bit of gut-feeling. Table 2 is a proposal for treatment guidelines for malignant canine mammary gland tumors according to established prognostic factors, results from published veterinary studies, and current recommendations for breast cancer treatment in women.  相似文献   
110.
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