紫花苜蓿夏季减产原因分析及评价紫花苜蓿抗热性指标筛选

发布时间：2018-05-03 21:12

本文选题：紫花苜蓿 + 茬　；参考：《河南农业大学》2015年博士论文

【摘要】：在我国中北部大田条件下,紫花苜蓿每年可收获3~6茬,据推测各茬次产量逐渐降低的变化规律是由于不同季节光温条件等环境不同所致。高温胁迫可能是夏季紫花苜蓿产量低的主要诱因。本研究的目的在于探讨适宜的环境条件下紫花苜蓿产量的变化规律,以及高温胁迫对其产量和形态的影响,为紫花苜蓿产量等指标的变化机理研究提供科学依据,并且建立快速准确的紫花苜蓿抗热性评价体系。1.为探讨紫花苜蓿随茬次产量逐渐降低原因,采用盆栽方法,将8个紫花苜蓿品种种植在智能温室内,保持一致的适宜温度、光照和水肥环境,探讨其各茬产量、叶绿素和光合速率的变化规律。为验证第1年得到的试验结果,第2年另选4个紫花苜蓿品种在相同生长条件下重复本试验。结果表明:在适宜的光、温、水肥条件下,紫花苜蓿第1~3茬产量逐渐升高,之后基本保持稳定,说明自然条件下紫花苜蓿每茬产量逐渐递减的规律是环境变化所致,在适宜生长的恒定的温度条件下紫花苜蓿各茬产量无显著差异。而且,第1~6茬初花期收获时株高、叶绿素含量和净光合速率变化不大,大部分茬次间差异不显著。相关分析表明,株高、单叶重与产量呈正相关,所以实际生产中应选择植株高大、分枝数多、大叶或多叶苜蓿品种以提高产量与品质。综合分析认为,紫花苜蓿在温室栽培条件下生长至一定时间时,产量可保持稳定。2.为探讨高温对紫花苜蓿产量和形态的影响。采用盆栽方法,将6个紫花苜蓿品种种植在2个生长培养箱内,2个培养箱温度(白天/黑暗)分别设置为25/20℃和35/30℃,测定其产量、株高、叶部特征及叶片叶绿素含量。结果表明,高温胁迫使紫花苜蓿生长受到抑制,植株矮小,产量降低54%;单叶片叶面积缩小至常温的四分之一,但叶片厚度增加了54%。综合上述结果可以看出,高温是生产中紫花苜蓿夏季减产的一个重要原因,紫花苜蓿对高温非常敏感,但会通过一系列形态上的变化来适应高温的胁迫。3.为了建立快速准确的紫花苜蓿抗热性评价体系,采用盆栽方法,将58个紫花苜蓿品种种植在智能温室,设置白天/黑暗温度为20/15℃,1个月后,将其转移至生长培养箱内,培养箱白天/黑暗温度设置为20/15℃,一周后升高温度为25/20℃,之后每1周升高1次温度并维持1周,温度升高后依次为30/25℃,35/30℃,40/35℃和43/40℃。选取一些可快速测定的指标:叶绿素荧光、叶绿素含量、相对含水量、可溶性糖含量、叶重和健康指数等,最后利用隶属函数来综合评价紫花苜蓿的抗热性并评价每个指标的可靠性。结果显示:温度增加使F0、叶绿素含量和可溶性糖含量升高,而Fv/m、相对含水量和叶重降低。在评价紫花苜蓿抗热性时相对含水量可靠性较差,F0、Fv/m、叶绿素含量、健康指数、可溶性糖含量和叶重可靠性较好。相关分析认为,常温时测定的叶绿素含量和叶重就可以用于评价品种的抗热性,并可用来估测其产量。
[Abstract]:In the northern part of China, the alfalfa can harvest 3~6 stubble every year. It is speculated that the gradual decrease in the yield of each crop is due to the different light and temperature conditions in different seasons. High temperature stress may be the main cause of the low yield of Alfalfa in summer. The purpose of this study is to explore the purple flower under the suitable environment conditions. The change rule of Alfalfa Yield and the effect of high temperature stress on its yield and morphology provide scientific basis for the study of change mechanism of Alfalfa Yield and other indexes, and a rapid and accurate evaluation system of Alfalfa heat resistance.1. is established to explore the gradual decrease of the yield of Alfalfa with the successive yield of stubble, and 8 purple flowers will be adopted by the pot culture method. The alfalfa varieties were planted in the intelligent greenhouse, keeping the appropriate temperature, light and water and fertilizer environment, and discussing the variation of the yield, chlorophyll and photosynthetic rate of each stubble. In order to verify the results obtained in first years, 4 alfalfa varieties were selected to repeat the experiment under the same growth conditions in second years. The results showed that the suitable light, temperature and water were suitable. Under the condition of fertilizer, the yield of Alfalfa 1~3 stubble increased gradually, and then remained stable. It indicated that the gradual decrease of the yield of Alfalfa under natural conditions was the result of environmental changes. There was no significant difference in the yield of Alfalfa under the constant temperature conditions. Moreover, the plant height of the first flowering period of the first 1~6 was high, chlorophyll The correlation analysis showed that plant height, single leaf weight and yield were positively related to yield, so plants should choose tall plants, many branches, large leaf or multileaf alfalfa varieties to increase yield and quality. At a certain time, the yield could be kept stable.2. to investigate the effect of high temperature on the yield and morphology of alfalfa. 6 alfalfa varieties were planted in 2 growth incubators by pot culture. The temperature of 2 incubators (day / darkness) was set at 25/20 and 35/30, respectively, and the yield, plant height, leaf characteristics and chlorophyll content of leaves were measured. The results showed that the growth of alfalfa was inhibited by high temperature stress, the plant was short, the yield was reduced by 54%, and the leaf area of single leaf was reduced to 1/4 of the normal temperature. But the results of the 54%. comprehensive results showed that the high temperature was an important reason for the reduction of alfalfa in the summer, and alfalfa was very sensitive to the high temperature. But through a series of morphological changes to adapt to the high temperature stress.3. in order to establish a fast and accurate evaluation system of the heat resistance of alfalfa, the 58 alfalfa varieties were planted in the intelligent greenhouse, and the temperature of daytime / darkness was 20/15 C. After 1 months, it was transferred to the incubator of growth and culture, and the incubator was in the daytime / darkness. The temperature was set at 20/15 C, and the temperature was 25/20 C after one week. After 1 Zhou Shenggao 1 temperatures and 1 weeks, the temperature was increased at 30/25, 35/30, 40/35 and 43/40. The chlorophyll fluorescence, chlorophyll content, relative water content, soluble sugar content, leaf weight and health index were selected. The membership function was used to evaluate the heat resistance of alfalfa and to evaluate the reliability of each index. The results showed that the increase of temperature made F0, chlorophyll content and soluble sugar content increase, while Fv/m, relative water content and leaf weight decreased. The relative water content of alfalfa was less reliable in evaluating the heat resistance of alfalfa, F0, Fv/m, chlorophyll content and health. The index, soluble sugar content and leaf weight reliability are better. The correlation analysis shows that the chlorophyll content and leaf weight measured at normal temperature can be used to evaluate the heat resistance of the varieties, and can be used to estimate their yield.

【学位授予单位】：河南农业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：S541.9

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