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Genetic shifts are predicted to be greatest when highly diversematerial originating from an arid environment is bulk multiplied inirrigated and fertilised conditions. This is a key problem if largequantities of quality native seed are needed for restorationpurposes. In Presaharian Tunisia, we investigated two intermingledyield aspects of irrigated seed multiplication of Stipalagascae R. and Sch.: (1) nitrogen fertilisationand (2) selection for vegetative vigour. We set up twocontiguous nitrogen fertilisation trials, one withnon-selected seeds (from a nearby locality), and onewith selected seeds (48 clonal lines seeded in replicatedrows), and compared straw yields. Both selected and unselectedmaterial did not respond to more than 50 kg of nitrogenper ha. Unfertilised yields of both trials were similar,but the straw yield of fertilised selected material was more than100% higher than the straw yield of fertilised unselectedmaterial. In the trial with selected material, we collected straw andleaf yields per row, and scored each row for vigour and for phenologyduring three successive growing seasons. Genotypic differences inseed output and in mortality were large and mainly driven byvariation in potential straw for leaf ratios.The compromise between high yields and high genetic variation couldconsist of the following principles. (1) Create driergrowing conditions so that the actual straw forleaf ratio stays below the genotypic potential. (2) Useinstead fertilisation and selection to enhance seed yields.(3) Avoid bulk multiplication. 相似文献
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以马兰头为试材,研究0.5μL/L的1-MCP和0.1 g/L的乙烯利处理对马兰头常温(20±1)℃货架品质的影响。结果表明,常温货架期间,0.5μL/L的1-MCP处理可保持马兰头叶片中较高的叶绿素含量,延缓可溶性蛋白、VC、h°值以及还原糖含量的下降,抑制失重率的上升和游离氨基酸的积累,从而提高了马兰头的贮藏品质,延长其货架期至105 h;而0.1 g/L乙烯利处理促进马兰头叶片失重率的上升、游离氨基酸的积累,加快VC、还原糖及叶绿素含量的下降,货架期提早结束。 相似文献
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为保护野生资源、满足栽培对种苗的需求,以裂叶马兰的嫩茎为外植体,进行愈伤组织诱导与分化、不定芽生根、试管苗生根继代增殖的研究,以及试管苗移栽和定植的研究,建立起裂叶马兰的无性系。结果表明:MS+蔗糖35 g·L-1+6-BA0.5mg·L-1+2,4-D2.5 mg·L-1是嫩茎愈伤组织诱导培养和继代增殖培养的适宜培养基;MS+蔗糖30 g·L-1+AgN031.0 mg·L-1+GA31.0mg·L-1+ZT1.6 mg·L-1+NAA0.1 mg·L-1是愈伤组织分化培养的适宜培养基;1/2MS+蔗糖20 g·L-1+NAA 0.6 mg·L-1是不定芽生根培养和试管苗生根继代增殖培养的适宜培养基;试管苗移栽成活率为95.9%;定植成活率98.0%。定植成活的试管苗保持了野生裂叶马兰的所有植物学性状。 相似文献
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建立测定雪莲(Saussurea involucrata)中绿原酸、芦丁和木犀草素含量的方法,采用HPLC法,色谱柱为Agilent Eclipse XDB-C18(250 mm×4.6 mm,5μm),乙腈-0.8%磷酸水溶液进行梯度洗脱,流速1.0m L/min,检测波长360 nm,柱温30℃。绿原酸、芦丁、木犀草素的线性范围分别为0.081~0.408μg/m L、0.090~0.449μg/m L、0.045~0.224μg/m L;平均加样回收率分别为99.78%、99.89%、100.70%,其中绿原酸、芦丁在天山雪莲中含量最高,木犀草素在苞叶雪莲中含量最高。 相似文献
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采用金沟岭林场30块样地8次观测数据,对3种异龄针阔混交择伐林均衡曲线确定方法进行比较。同时,引入方差值对现有林分的直径分布进行结构稳定性判断,通过非线性规划模型对现有的直径分布进行结构优化调整,并利用矩阵法预测下一周期的直径分布。结果表明:De Liocourt均衡曲线是一个理想状态的曲线;López均衡曲线在不考虑采伐或各径级采伐率相等的情况下比较适用;Schütz均衡曲线既考虑了树木的生长信息,也包括了林分的采伐和枯损信息,较好地描述了林分的真实情况;分别以这3种均衡曲线为标准,对现有林分的直径分布进行结构优化调整后,下一周期的直径分布趋向于稳定。 相似文献
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将宁夏小麦赤霉病禾谷镰刀菌单饱分离的纯培养菌系10个有效菌株,分别接种在12个小麦品种和宁夏主栽小麦品种永良4号上,结果表明,禾谷镰刀菌系间存在较明显的致病性分化现象,对于不同品种其致病力不同,菌系和小麦品种间均表现出不同的反应。将宁夏小麦赤霉病禾谷镰刀菌的70个单孢纯培养菌株接种在宁夏主栽品种永良4号上,结果显示中致病力菌株占41.4%,弱致病力菌株占40%,强致病力菌株占18.6%。 相似文献
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