【作者】 陈自惠；

【导师】 田霄鸿；

【作者基本信息】 西北农林科技大学 ， 植物营养学， 2009， 硕士

【摘要】 锌是动植物生长所必需的微量元素,通过植物进入食物链,直接或间接进入人类的膳食中,进而影响人体的营养平衡及身体健康。小麦是世界上播种面积最大和总产量最多的粮食作物,同时也是对锌比较敏感的作物之一。而缺锌人群主要分布在动物性食物摄入量较低,以小麦或水稻等禾谷类作物为主食的发展中国家。因此,小麦籽粒中锌含量水平高低直接影响着人类健康状态,而解决此问题最有效的办法是锌高效基因型小麦和籽粒富锌小麦的筛选及施用锌肥。本研究通过2个水培试验,比较了不同小麦品种的锌效率,探讨了锌供应方式对小麦生长及锌等养分吸收利用的影响,以期为提高小麦营养品质提供理论和实践依据。本研究主要得到以下结论:(1)为了比较不同小麦品种的Zn效率,采用螯合-缓冲营养液培养方法,以9种面包型小麦(渭丰151,陕715,郑麦9023,中育6号,小偃22,武农148,小偃216,西农889,远丰175)为供试材料,以黑麦(Secale cereale)为对照,设不供锌(-Zn)和供锌(+Zn,3μmol/L)2种处理,进行为期35 d的水培试验。培养2周后,缺Zn条件下9个小麦品种植株均出现典型的缺Zn症状,并且缺Zn症状随着培养时间的延长而更加严重。缺Zn导致小麦地上部干质量大幅度下降,而根系所受的影响相对较小;6个小麦品种(渭丰151,郑麦9023,远丰175,小偃22,西农889,中育6号)在供Zn时其地上部干质量接近,但在缺Zn时差异很大。9个小麦品种的Zn效率为23.6 %～46.3 %,远低于黑麦的Zn效率(81.4 %)。供Zn后,小麦植株地上部Zn含量和Zn吸收量均显著提高,但黑麦地上部Zn含量变化不大。缺Zn时小麦Zn效率与植株地上部Zn吸收量之间存在显著正相关关系,但与植株地上部Zn含量无明显相关性;Zn效率与种子Zn含量和Zn总量之间均不存在显著相关性。(2)为了揭示根部供Zn(营养液供Zn)和不同生育期地上部喷Zn对小麦生长及籽粒Zn含量的影响,对2种Zn效率不同的冬小麦种子进行人工春化后发芽,并在完全营养液中培养25 d后进行不同方式供Zn处理,进行了全生育期水培试验。结果表明,分别与营养液不供Zn和地上部不喷Zn相比,营养液供Zn和不同生育期地上部喷Zn均显著促进了小麦生长,而小偃22生物量显著高于郑麦9023。营养液供Zn和不同生育期喷Zn均增加了小麦的冠根比。营养液不供Zn条件下,郑麦9023的冠根比显著大于小偃22,是后者的1.28倍,说明小偃22对缺Zn的反应更敏感,而郑麦9023的Zn效率更高。营养液供Zn显著提高了2种基因型小麦各器官Zn含量和吸收量。与营养液不供Zn相比,营养液供Zn使根、茎、叶、籽粒Zn含量分别增加了568.7%、355.2%、138.0%、83.8%;Zn吸收量依次增加了607.3%、366.9%、122.5%、113.2%,可见,营养液供Zn时根部Zn含量和吸收量增加幅度最大。喷Zn显著降低了小麦根部Zn含量和吸收量,而显著增加了地上部Zn含量和吸收量,抽穗期喷Zn小麦地上部Zn吸收量最大。与营养液不供Zn相比,营养液供Zn时小麦地上部和籽粒Zn累积率较低。对于小偃22,与地上部不喷Zn相比,地上部喷Zn时其地上部Zn累积率较高。对于郑麦9023,与地上部不喷Zn相比,地上部喷Zn时其籽粒Zn累积率较高。分别与营养液不供Zn和地上部不喷Zn相比,营养液供Zn和地上部喷Zn时小麦Zn利用率均较高。(3)不同供Zn方式对小麦生长及籽粒Zn含量的试验结果还表明:营养液供Zn条件下,2种基因型小麦植株体内的Fe含量略有下降,吸收量却有所增加;Cu含量和吸收量均显著下降;根系Mn含量和吸收量显著上升,地上部刚好相反;N含量显著下降,吸收量却有所增加;根系P含量和吸收量显著上升,地上部P含量有所下降,地上部P吸收量却有所增加;植株K含量有所下降,吸收量却有所增加。地上部喷Zn条件下,促进了植株对Fe的吸收,转运率变化不大;植株体内Cu含量下降,促进了对Cu的吸收,但茎部吸Cu量却有所下降;明显抑制了叶片对Mn的吸收,但促进了其它器官对Mn的吸收,转运率略有下降;各器官N含量下降,但植株对N的吸收显著增加;明显促进了对P的吸收,P转运率大幅度上升;促进了对K的吸收,K在叶部大量累积。综上所述,面包型小麦对缺Zn的耐性存在较大的基因型差异,螯合-缓冲营养液培养方法下的Zn效率可以作为筛选面包型小麦对缺Zn耐性的一个可靠指标。与营养液供Zn的结果相反,地上部喷Zn可以同时提高小麦地上部和籽粒Zn累积率。营养液供Zn时,Fe、Cu在根部大量累积,Mn在叶部大量累积;地上部喷Zn对小麦养分吸收影响显著,尤其是抽穗期和扬花期。更多还原

【Abstract】 Zinc is an essential micronutrient for plant and animal growth, it enters into the food chain through plant, then it enters the diets of human being directly or indirectly, thereby it affects the balance of nutrition and the health of buman being. Wheat is the food crop with the largest planting area and total yield, while it is more sensitive to Zn. The Zn-deficienct people manily live on cereal crops sucn as wheat or rice as their staple food and have less animal food injestion and most of them live in developing countries. So Zn concentration of wheat directly affects the health of buman beings, and the most effective approach to solve this problem is screening the wheat genotypes with high Zn-efficiency or high seed Zn or fertising Zn at present. In this study two solution culture experiments were conduted to compare Zn efficiency of different wheat genotypes and discuss the effect of different applying methods of Zn fertilization on wheat growth and nutrient uptake especially Zn accumulation in the aboveground parts and grain. This research will provide theoretical and practical value for improving nutritional quality of wheat. The main results of this study were as follow:(1) In order to compare Zn efficiency of different wheat cultivars, chelator-buffered nutrient solution culture was conducted, nine bread wheat (WF151, S715, ZM9023, ZY6, XY22, WN148, XY216, XN889, YF175) cultivars and one rye cultivar (Secale cereale, control) were grown in the solution for 35 d with (+Zn, 3μmol/L) and without (-Zn)Zn supply. All of the wheat cultivars showed visual symptoms of Zn deficiency under no Zn supply after two weeks of culture, and the symptoms became more serious with time. Zn deficiency resulted in a marked decrease in shoot dry weight , but it had relatively slighter influence on root. Six cultivars (WF151, ZM9023, YF175, XY22, XN889, ZY6) were similar in shoot dry weight under Zn supply; however, they showed great variation under Zn deficiency. The Zn efficiency of the nine wheat cultivars ranged between 23.6 % to 46.3%, which were greatly lower than that of rye (81.4%). Under adequate Zn supply, shoot Zn concentration and Zn content of wheat cultivars were significantly increased, but shoot Zn concentration of rye did not change much. There was a very significant positive correlation between shoot Zn content and Zn efficiency of wheat cultivars under no Zn supply, but shoot Zn concentration was not significantly correlated with Zn efficiency, at the same time, there was not a significant correlation between Zn efficiency and seed Zn concentration or Zn content.(2) In order to disclose the effect of supplying Zn in root (supplying Zn in nutrient solution) and spraying Zn in shoot in different growth stage on wheat growth and grain Zn concentration, two winter wheat with different Zn efficiency germinated after they were vernalizated, then they grew in the complete nutrient solution for 25 d, at last they were treated in different methods of Zn supply. This was a whole growth period experiment. The obtained results showed that, compared to no Zn in the nutrient solution and no spray Zn in shoot separately, supplying Zn the in nutrient solution and spraying Zn in shoot both significantly enhanced wheat growth, and the biomass of Xiaoyan22 significantly higher than that of Zhengmai9023. Supplying Zn in the nutrient solution and spraying Zn in shoot both significantly enhanced the shoot to root ratios. Under the condition of no Zn in the nutrient solution, the shoot to root ratio of Zhengmai9023 significantly higher than that of Xiaoyan22, which showed that the response of Xiaoyan22 to no Zn supply was more sensitive, and the Zn efficiency of Zhengmai9023 was higher. Supplying Zn in the nutrient solution significantly enhanced the Zn concentration and content of various organs of two cultivars of wheat. Compared to no Zn in the nutrient solution, Zn concentration of root, stem, leaf, grain separately increased by 568.7%, 355.2%, 138.0%, 83.8%, and Zn content of them separately increased by 607.3%, 366.9%, 122.5%, 113.2% when supplying Zn in the nutrient solution, which showed that the increase extent of root Zn concentration and content was the largest under the condion of supplying Zn in the nutrient solution. Spraying Zn in shoot significantly decreased root Zn concentration and content, while significantly increased shoot Zn concentration and content and shoot Zn content was the highest when spraying Zn on the heading stage. Compared to no Zn in the nutrient solution, the Zn accumulation ratio of shoot was lower when supplying Zn in the nutrient solution. The Zn accumulation ratio of shoot of Xiaoyan22 was higher under the condition of spraying Zn in shoot than that of no spraying Zn. The Zn accumulation ratio of grain of Zhengmai9023 was higher under the condition of spraying Zn in shoot than that of no spraying Zn. Compared to no Zn supply in the nutrient solution and no spray Zn to shoot separately, the Zn utilisation of wheat was higher when supplying Zn the in nutrient solution and spraying Zn to shoot.(3) The experiment of effect of different Zn supplying methods on wheat growth and grain Zn concentration also showed that, under the condition of supplying Zn in the nutrient solution, Fe concentration slightly decreased, but Fe content slightly increased, both Cu concentration and content slightly decreased, Mn concentration and content of root significantly enhanced, but shoot Mn concentration and content significantly decreased. N concentration significantly decreased, but N content slightly increased, root P concentration and content significantly increased, shoot P concentration slightly decreased, shoot P content slightly increased, K concentration slightly decreased, but K content slightly enhanced. Under the condition of spraying Zn in shoot, Fe uptake increased, but its translocation ratio did not change much, Cu concentration of wheat decreased and Cu uptake increased, but Cu content of stem slightly decreased. Spraying Zn significantly restrained the Mn uptake of leaves, but stimulate the Mn uptake of other organs, Mn translocation ratio slightly decreased, at the same time, it declined N concentration, but significantly enhanced N, K, and P uptake, a great deal of K accumulated in leaves.In a word, the results of the present study showed existence of a large variation in tolerance to Zn deficiency among the different cultivars of bread wheat, suggesting that Zn efficiency can be used as a reliable plant parameter for screening the bread wheat genotypes for their tolerance to Zn deficiency. In opposition to supplying Zn in nutrient solutin, spraying Zn in shoot could both enhance Zn cumulation ratio of shoot and grain. Under the condition of supplying Zn in nutrient solution, a great deal of Fe and Cu accumulated in root and a great lot of Mn accumulated in leaves. Spraying Zn in shoot also had a significant influence on the nutrient uptake, especially spraying Zn on the heading and flowering stage.更多还原