基于生态足迹模型的西北干旱绿洲农业区可持续发展评价——以张掖市为例

利用生态足迹和生态承载力的理论和方法,以西北干旱绿洲农业区城市张掖为例,对其可持续发展状况及程度进行了评价和度量。结果表明：张掖市2009年人均生态足迹为3.798hm2,人均承载力为1.453hm2,人均生态赤字为2.345hm2。在此基础上,对张掖市的生态可持续发展进行了评价,并提出解决对策。     

甜叶菊栽培研究进展

通过对品种、茬口、栽培措施及光照要求等方面的研究文献进行综述，归纳了目前甜叶菊栽培方面的研究动态和存在的问题，为今后甜叶菊的栽培研究提供参考。     

天仙子种子浸提液对黑麦草种子萌发和幼苗生长的化感作用

为了探究天仙子（Hyoscyamus niger L.）对禾本科牧草的化感作用,以天仙子和黑麦草（Lolium perenne L.）为材料,通过5个不同浓度天仙子种子浸提液（0,0.025,0.05,0.075,0.1 g·mL^-1）,对黑麦草种子萌发和幼苗生长进行处理,测定黑麦草种子萌发和幼苗生长情况。结果表明：不同浓度的天仙子种子浸提液对黑麦草种子萌发有极显著影响（P<0.01）,随浸提液浓度增加,黑麦草萌发率和发芽指数显著降低（P<0.05）;浸提液对黑麦草根长和地上、地下生物量有显著的影响（P<0.05）,对株高影响不显著;不同浓度的天仙子种子浸提液处理下,黑麦草幼苗丙二醛、脯氨酸含量、相对电导率均随浸提液浓度的增加而增加,叶片中叶绿素含量则随浸提液浓度的增大而减小。综上所述,天仙子种子浸提液对黑麦草幼苗细胞膜具有一定的损伤作用,黑麦草植株通过细胞膜的变化而影响内部生理生化过程,以适应不利的环境。     

A longitudinal study of the effect of time on the matching performance of a retinal recognition system for lambs

While there is strong evidence supporting retinal vascular pattern as a distinctive marker for sheep, it would be advantageous to get an insight into its robustness; in other words, to determine whether retinal recognition of young animals (lambs) can reach as good a matching performance as the one demonstrated for adult sheep. To this aim, a longitudinal study was devised to observe the evolution of matching scores (ms) of lamb retinal images (n = 38) acquired from 1 to 22 weeks after birth. It was observed that four lamb retinas (out of 38) underwent slight curving of one or two secondary arteries, which ceased by the time they were 6–8 weeks old. However, this slight artery curving did not affect matching performance. A random effects statistical model demonstrated that lamb age had an effect (P < 0.01) on the matching scores produced using this commercially available retinal recognition system. As lambs grew older (larger eyes) and they became easier to handle, retinal images of progressively better quality could be obtained in a more consistent way; and thus matching scores increased from an average of 86 at the first week of life, up to an average of 96 by week 8. Dunnett simultaneous tests of means indicated that no further improvement in matching score took place once lambs were at least 6–8 weeks old, meaning that the retinal image quality became by then optimal and consistent. Although the variable retinal image quality of younger lambs (1–4 weeks old) caused a reduction in matching score, they did not lead to false non-matches in any case (considering a cut-off matching score of 70 for acceptance of a positive match). Therefore, the results of these trials have shown that, with the available technology, retinal images can be used as a robust biometric marker of lambs from 1 week of age.     

Characterization of ethylene biosynthesis and its regulation during fruit ripening in kiwifruit,Actinidia chinensis ‘Sanuki Gold’

Ethylene biosynthesis in kiwifruit, Actinidia chinensis ‘Sanuki Gold’ was characterized using propylene, an ethylene analog, and 1-methylcyclopropene (1-MCP), an inhibitor of ethylene perception. In fruit harvested between a young stage (66 days after pollination) (DAP) and an early commercial harvesting stage (143 DAP), 2 days of exposure to propylene were sufficient to initiate ethylene biosynthesis while in fruit harvested at commercial harvesting stage (154 DAP), 4 days of propylene treatment were required. This observation suggests that response of ethylene biosynthesis to propylene treatment in kiwifruit declined with fruit maturity. Propylene treatment resulted in up-regulated expression of AC-ACO1, AC-ACO2, AC-SAM1 and AC-SAM2, prior to the induction of AC-ACS1 and ethylene production, confirming that AC-ACS1 is the rate limiting step in ethylene biosynthesis in kiwifruit. Treatment of fruit with more than 5 μL L^?1 of 1-MCP after the induction of ethylene production subsequently suppressed ethylene production and expression of ethylene biosynthesis genes. Treatment of fruit with 1-MCP at harvest followed with propylene treatment delayed the induction of ethylene production and AC-ACS1 expression for 5 days. These observations suggest that in ripening kiwifruit, ethylene biosynthesis is regulated by positive feedback mechanism and that 1-MCP treatment at harvest effectively delays ethylene production by 5 days.     

黑果枸杞根系构型对干旱胁迫的响应机制

【目的】探讨黑果枸杞幼苗根系构型对干旱胁迫的响应机制,为黑果枸杞的种植、种群恢复和合理利用及其他旱生植物研究提供理论依据。【方法】以盆栽黑果枸杞幼苗为研究对象,采用控水法,设置正常供水（20.97%）（对照, CK）、轻度胁迫 （15.51%）、中度胁迫 （3.42%）、重度胁迫 （2.35%）和极重度胁迫 （1.45%）5个胁迫梯度,通过对比不同胁迫梯度对黑果枸杞幼苗根系拓扑指数、拓扑结构、生物量及相关根系形态指标的影响,分析黑果枸杞幼苗根系构型对干旱胁迫的响应。【结果】干旱胁迫下,黑果枸杞根系构型趋向于叉状分支模型。随干旱胁迫程度的增加,黑果枸杞幼苗根系由叉状分支向鱼尾形分支过渡;幼苗地上生物量、地下生物量和总生物量均呈现先增加后减少的趋势,且地上生物量和总生物量在不同处理间差异显著 （P<0.05）。与CK相比,轻度和中度胁迫下总生物量分别增加82.47%和41.09%。根冠比呈现逐渐增加的变化趋势;根长、根表面积和根体积均呈现出先增加后减小的变化趋势;而比根长和比表面积呈逐渐减小的变化趋势,轻度、中度、重度和极重度胁迫分别降低7.73%、 10.25%、 60.62%和77.09%,比表面积分别减小17.59%、 30.04%、 80.15%和83.40%。不同径级根长、根表面积和根体积均在轻度胁迫时达最大值,根长和根表面积随干旱胁迫程度的增加各径级排序依次为0~0.5 mm>0.5~1.0 mm>1.0~1.5 mm>1.5~2.0 mm>2.0~2.5mm。【结论】黑果枸杞的生长受干旱胁迫的影响,其根系不同形态指标及根系构型存在差异。轻度干旱胁迫有利于黑果枸杞幼苗根系正常生长,但黑果枸杞的耐受程度存在阈值,土壤含水量为15.51%时生长最佳。     

大花飞燕草色素提取及其稳定性考察

以大花飞燕草为原料提取色素,通过响应面法优化工艺条件,并考察其稳定性。结果表明,大花飞燕草色素的最佳提取工艺为：提取时间49．5min,提取温度48℃,料液比1：49g／mL,乙醇浓度为95％,稳定性试验表明,大花飞燕草色素在pH值为3-6的范围内较为稳定,温度超过70℃稳定性较差,光照会使色素稳定性明显下降。Fe^3＋使色素稳定性明显下降,K^＋、Na^＋、Mg^2＋、Zn^2＋对其基本无影响,NaCl、蔗糖、山梨酸钾、苯甲酸、柠檬酸、VC、Cu^2＋和Al^3＋对其具有护色作用。     

高温胁迫对玉米自交系父本花粉生活力的影响

以中种集团提供的10份骨干玉米自交系父本花粉为试验材料,通过TTC染色法和离体培养法,研究不同胁迫温度对花粉生活力的影响。结果表明,玉米花粉不易储藏,高温胁迫会导致花粉生活力显著下降,在35℃胁迫处理6 h之后花粉生活力全部丧失;在40℃胁迫处理4 h之后有8个自交系的花粉丧失生活力。TTC染色法和离体培养法均能有效测定玉米花粉生活力,离体培养法测得的花粉生活力低于用TTC法测得的水平。     

干旱胁迫与复水对玉米苗期渗透调节物质及抗氧化酶的影响

以掖单13号（抗旱性弱）和农大108（抗旱性强）为试材,采用盆栽控水的方法,研究了不同程度的干旱胁迫与复水条件对玉米苗期渗透调节物质及抗氧化酶的影响。结果表明,玉米苗期可溶性糖、蛋白质和脯氨酸的积累与品种的抗旱性呈负相关,抗旱性与水分胁迫下抗氧化酶类活性呈显著负相关,其中SOD和POD为主要抗氧化酶。     

不同叶面肥对葡萄果实品质的影响

以“矢富罗莎”、“红提”葡萄为试材,研究了喷施串串金、绿威、绿霸之星、佰旺四季叶面肥对葡萄果实生长和品质的影响.结果表明:葡萄喷施不同叶面肥后,果实的单粒重、纵横径、硬度、维生素C含量、可溶性糖、糖酸比均有提高,有机酸含量降低,不同的叶面肥之间存在差异,以串串金葡萄专用叶面肥效果最为明显.