论文标题:不同灌水处理对生菜生长和品质的影响
Effects of Different Irrigation Quantity Treatments on the Growth and Quality of Lettuce
论文作者
论文导师 别之龙,论文学位 硕士,论文专业 设施园艺学
论文单位 华中农业大学,点击次数 135,论文页数 64页File Size3511K
2007-06-01论文网 http://www.lw23.com/lunwen_877089447/
Lettuce;; irrigation maximums;; irrigation minimums;; growth;; physiological;; quality
水资源短缺已成为制约农业生产可持续发展和生态环境改善的瓶颈，是限制蔬菜产量提高的重要因子。因此，有关蔬菜作物的需水规律和土壤水分对蔬菜的生理影响研究一直是生理生态研究的热点之一。国内外有关蔬菜灌溉指标的研究较多，但是都主要集中在果菜类蔬菜上，如黄瓜、番茄等，而对叶菜类蔬菜研究较少。生菜是叶菜类蔬菜的典型代表，但目前尚未见到关于生菜与水分灌溉之间的研究报导。本试验以两个散叶生菜品种(“弘农”和“绿领”)为材料，采用滴灌方式研究了不同灌水处理对生菜生长和品质的影响。试验由不同灌水量处理、不同灌溉上限处理、不同灌溉下限处理对生菜生长和品质的影响三部分组成。 1．利用四种不同灌水定额(100ml，75ml，50ml和25ml)处理研究了其对生菜生长和品质的影响。结果表明，随着灌水量的减少，生菜地上部的鲜重、叶面积、叶片数、叶片含水量显著降低，叶绿素含量、生菜叶片光合速率、蒸腾速率和气孔导度亦显著降低。生菜可溶性糖、可溶性蛋白、维生素C含量呈增加趋势。对叶绿素荧光参数的分析表明，Fv／Fm、Fv／Fo、qP随着灌水量降低而逐渐减小，而qN则随着灌水量降低而增加。地上、地下部矿质元素含量也随着灌水量的减少呈降低趋势，其中N、K、Mg三种元素降低趋势明显。 2．采用不同灌水量上限(60％-100％、60％-90％、60％-80％、60％-70％)处理研究了其对生菜生长、品质和生理特性的影响。收获期测定的结果表明，90％灌水量上限条件下生菜地上部干鲜重、叶面积、叶片数均最高，80％灌水量上限下生菜地上部的生长优于100％灌水量上限处理。随着灌水量上限的降低，生菜可溶性糖、可溶性蛋白含量逐渐升高，80％和70％灌水量上限处理下的维生素C含量显著高于其他两个灌水量上限处理。生菜叶片PSⅡ实际光化学效率(PSⅡ)逐渐下降，而非光化学淬灭系数(qN)逐渐增加，处理Ⅳ条件下达到最大，分别比处理Ⅰ增加了63.0％(弘农)和75.9％(绿领)。70％的灌水量上限处理下生菜叶片中的MDA、SOD、CAT和Pro含量最高，膜脂过氧化程度最重。本试验的结果表明，90％灌水量处理下生菜的产量最高，综合不同灌水量上限处理对产量和品质的影响，80％的灌水量上限处理是最适合生菜生长的灌水处理。 3．采用不同灌水量下限(70％-90％、60％-90％、50％-90％、40％-90％)处理研究了其对生菜生长、品质和生理特性的影响。结果表明，70％灌水量下限条件下生菜地上部干鲜重、叶片含水量、叶面积、叶片数均最高。随着灌水量下限的降低，生菜可溶性糖、可溶性蛋白含量逐渐升高，50％灌水量下限处理下的维生素C含量显著高于其他三个灌水量下限处理。两个生菜品种MDA、SOD、CAT和Pro含量也随着灌水量下限的降低而呈递增趋势。对叶绿素荧光参数的分析表明，Fv／Fm、Fv／Fo、qP随着灌水量下限降低而逐渐减小，而qN则随着灌水量下限降低而增加。从产量和品质两方面考虑，60％灌水量下限产量降低不多，又增加了生菜品质，是最适合生菜生长的灌水量下限处理。
Shortage of water has been a problem which has a strongly inhibitory effect on agriculture sustainable development and entironment improvement, and is also a key point to improve production of vegetable. So investgation on water-use-rule of vegetables and effects of water on vegetables physiology is one of the hotpots of physiology and bionomy reserach all the time. There were many investgations on vegetable irrigation, but they almost focused on fruit vegetables, like cucumber, tomato and so on, while few of them were about leaf vegetables. Lettuce is a kind of representative leaf vegetables, but there were few reports about the relationship between letttce and irrigation till now. In this study effects of different irrigation treatments on the growth, quality of two lettuce cultivars (cv. Hongnong and Lvling) were investigated. The study was made up of three parts: different irrigation quantity treatment, different irrigation maximums treatment and different irrigation minimums treatment. 1. The effects of different irrigation quantity(100ml, 75ml, 50ml and 25ml per plant)on the growth and photosynthesis of two lettuce cultivars(cv. Hongnong and Lvling) were investigated. The results showed that shoot fresh weight, leaf area, leaf number and water content decreased significantly with diminish of irrigation quantity. Leaf chlorophyll content, photosynthetic rate, transpiration rate and stomata conductance decreased with the decrease of irrigation quantity. Fv/Fm, Fv/Fo and qP decreased whereas qN increased with decreasing of irrigation quantity. The mineral content decreased as irrigation quantity, N、P、K content decreased significantly. 2. The effects of different irrigation maximums (60%-100%、60%-90%、60%-80%, 60%-70%) on the growth, quality and physiological characteristics of two lettuce cultivars were investigated. The results showed that the greatest shoot fresh and dry weight, leaf area and leaf number were obtained in 90% irrigation maximum treatment, soluble sugar, soluble protein of lettuces gradually increased with the decrease of irrigation maximums, the vitamin C contents of lettuces under 80% and 70% irrigation maximums were significantly higher than those of other treatments. The highest contents of MDA, SOD, CAT and Pro were obtained in 70% irrigation maximum treatment. The results also showed that the highest yield was obtained in 90% irrigation maximum treatment. But as a whole 80% irrigation maximum treatment was the most proper irrigation treatment. 3.The effects of different irrigation minimums (70%-90%、60%-90%、50%-90%、40%-90%) on the growth, quality and physiological characteristics of two lettuce cultivars were investigated. The results showed that the greatest shoot fresh and dry weight, leaf area and leaf number were obtained in 70% irrigation minimum treatment. soluble sugar, soluble protein of lettuces gradually increased with the decrease of irrigation minimums, the vitamin C, content of lettuces in 50% irrigation minimums were significantly higher than that in other minimums treatments. The contents of MDA, SOD, CAT and Pro increased with the decline of irrigation maximum, whereas chlorophyll fluorescence parameters showed that Fv/Fm、Fv/Fo、qP gradually decreased with the decline of irrigation minimums, but qN was the opposite. Taking the quantity and quality into consideration, in 60% irrigation minimum treatment, lettuces could gain a better quality but a slightly decrease in quantity. So 60% irrigation minimum treatment was suitable for lettuce.
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