【作者】 化党领；

【导师】 韩锦峰； 介晓磊；

【作者基本信息】 河南农业大学 ， 作物栽培学与耕作学， 2003， 博士

【摘要】 钾对于小麦高产与优质都具有重要的、不可替代的作用。在钾肥资源有限和土壤矿物钾未能高效利用的情况下，筛选和培育耐低钾和钾高效小麦基因型具有营养学和战略上的意义。 本研究历时两年多，通过水培、盆栽、大田和室内测定，从不同基因型小麦生长与钾吸收利用、根细胞质膜氧化还原系统和根ATP酶几方面分析比较了53个小麦基因型的K营养特性差异及内在生理机制，关于小麦钾营养吸收这一研究领域的理论认识、试验手段和部分结果都具有创新意义。研究结果如下： 小麦苗期营养吸收与生长表明，茎叶干重增加与吸钾量增加二者变化趋势大致相同，表明吸钾量的增加是茎叶干重和根干重增加的主因。小麦品种远丰898表现在钾胁迫时生物产量很高而在钾充足时也有较大的潜力。虽然周13在高钾时生物重大，但在K不足时生物重最小。豫农015和百农64干重也较低。小麦体内K水平影响对外部K的吸收，温6-986和周13吸收较快，豫农015和高优503吸收较慢。各品种平均生长速率豫农015最低，高优503、远丰898和温6-986较高。两种K浓度培养的小麦百农64和周13的V_max较大，新9和温6-986的K_m较小。K_m和V_max在两个K水平下数值不同，表明动力学参数的测定易受体内营养状况的影响。吸钾所伴随的pH变化大致分两个阶段，植株放入吸收溶液的初始时期，pH值均有一下降阶段；然后又有一回归性升高阶段。前一阶段对应着溶液钾的快速下降阶段，即迅速的钾吸收可能与质子分泌相伴；后一阶段似乎对应着净钾吸收为零阶段。由于吸钾过程和吸钾量都与pH改变无显著相关，所以通过测定pH变化判断小麦K吸收能力并不可靠。高钾下K利用效率较低钾下降低，而且利用效率大小顺序也有所改变。新9的K利用效率在高、 中义摘要低 K下均最低。从低钾下茎g－＋干重看，郑 9023、远丰 898和百农 64产生较多的生物量，新 9、温 10和温 6q86生物量较少。从相对生物量和低 K下钾利用效率看，远丰898和郑9023也较大，新9和温6－986较小。女果从小麦营养器官生物量、相对生物量和利用效率看，郑9023和远丰898应该划作耐低钾和钾高效品种，新9应归不耐低钾和钾低效一类。植株各部分的氮磷吸收绝对量是随K供应的增加而提高。比较不同基因型，氮、磷和钾吸收总量以远丰898和周门较大。KO（钾胁迫）时茎叶干重和吸N量可以作为耐低钾或钾效率的指标。随着K供应的增加，吸N量、吸K量和茎叶干重的变异系数渐增。三个K供应水平下K利用效率的排序可看出，远丰898、高优503和温6q86的K利用效率稳居前三位，尤其是远丰898更为突出。考察营养效率必须考虑营养供应水平。因为在低营养水平具有相对高的吸收和利用营养能力的基因型未必对增加的营养有较好反应。低钾时茎叶干重的差异或者说钾使用效率的差异主要是因为钾利用效率的差异而不是吸收效率的差异；高K时茎叶干重的差异或者钾使用效率的差异卞要是因为吸收效率的差异而不是刊用效率的差异。研究开花前后营养的再分配规律，可以了解各个元素及不同基因型的养分吸收和再利用特性。 不同品种小麦根质膜NADH氧化速率不同，高优503在20min内的氧化速率明显高于其它7个品种。kKN／还原速率以远丰898和郑9023较大，周 13和豫农 of 5较小。NAD瞩)Hfe抖鳌合物还原酶活性以周 13、新9和远丰 898较大，郑 9023和豫农 of 5较小。铁氰化钾还原引起的介质酸化是一个明显而普遍的现象。小麦根系在反应液中，加入外部电于受体Fe（CN）6－之后，不但增加了H”的外泌，也影响了根系K”的含量。远丰898和温6习86因铁氰化钾的还原而使根中K“含量上升，其它6种因铁氰化钾的还原而导致根中K”含量下降，铁氰化钾还原及其引起的K”迁移两个变量之间有一定的相关性。H”分泌与铁氰化钾还原之间没有明显的相关。幼 VI 论义题U：个M杜H型小左仰效个差异及生埋机制苗质膜 H＼ATPase活性以百农 64、远丰 898、豫衣 015品种较大，新 9活性最低。钾胁迫条件下，所有品种的根质膜＊＼AT P酶活性均受＊Q刺激而活性增加。生长 35d的麦茁在K充足和 K胁迫条件下新麦 9号活性排序均提前，表明酶活性可能与生长期有关。K充足条件下的小麦根ATP酶明显地显示三条谱带。K胁迫条件下根内ATP酶与K”充足条件下相比，有明显变化，豫农 of 5和百农 64的三条主要谱带消失。K充足条件下可溶性蛋白酶谱中的几条弱带在K胁迫条件下显著减弱，有些品种几乎消失，不同品种间看不出谱带的不同八H与口－I－。户可溶性蛋白及AT P酶相比，有明显不同。根与日－！l。卜的可溶蛋臼于各品利啊没有看到差异。更多还原

【Abstract】 Potassium is indispensable for the high yield and high quality in wheat production. It is very important to screen and breed wheat varieties with characteristics of low potassium tolerance and potassium-efficient.The study was undertaken by hydroponics, pot cultivars and field trial to study the nutrient absorption and growth, redox system and ATPase in the plasma membrane of wheat root cell aimed to elucidating the differences in potassium efficiency and its intrinsic physiological mechanism among different wheat genotypes.The increase of straw accords with the increase of potassium acquisition, indicating that potassium is a primary cause of dry matter increase. Yuanfeng898 has the higher weight of biomass irrespective of potassium stress and potassium sufficiency.Zhou13 has higher weight under potassium sufficiency but lower under potassium deficiency.Yunong015 and Bainong64 have lower weight of biomass under two conditions respectively. The content of potassium in seedlings impact on the potassium uptake successively. The Wen6-986 and ZhoulS absorb potassium rapidly and YunongO 15 and Gaoyou503 absorb it slowly.Gaoyou503,Yuanfeng898 and Wen6-986 have the higher average growth rate,Yunong015 growed slowly. The potassium uptake kinetics parameters Vmax values of Bainong64 and Zhou13 are high, the Km values of Xin9 and Wen6-986 are small. pH change concomitantly with potassium uptake, this process was identified for two phases: pH declined at primary stage coincided with potassium acquiring quickly and maintained constantly at the next stage as no potassium uptake. It is susceptible to identifying potassium uptake efficiency by pH change because no correlation exists in the process and magnitude between pH change and potassium uptake. The potassium utilization efficiency under high potassium condition is higher then that of low potassium and the rank for potassium utilization differ under two potassium level. The potassium utilization efficiency value of Xin9 is the lowest among all strains irrespective of potassium values.Zheng9023,Yuanfeng898 and Bainong64 yielded more dry matter, Xin9,WenlO and Wen6-986 yielded less dry matter under low potassium.Yuanfng898 and Zheng9023 had higher values of relative biomass compared between low potassium and high potassium and potassium utilization efficiency under low potassium.Zheng9023 and Yuanfeng898 should be identified as potassium-tolerance or potassium-efficient strains, and Xin9 be potassium -inefficient based on vegetative growth, relative biomass and potassium utilization efficiency. The amount of nitrogen and phosphorus uptake in different organs on wheat was improved with the increase of potassium employed. The amount of nitrogen, phosphorus andpotassium absorbed in Yuanfeng898 and Zhoul3 seedlings are higher among varied genotypes. The dry matter of stem plus leaf and value of nitrogen acquisition under potassium stress should be used to evaluate potassium use efficiency or degree of potassium tolerance. The variance coefficients for dry matter of stem plus leaf, value of nitrogen and phosphorus acquisition increase as potassium elevated. Rank of potassium utilization efficiency under three potassium concentration treatments show that Yuanfeng898,Gaoyou503 and Wen6-986 are higher then others, especially Yuanfeng898.To evaluate nutrition use efficiency ,We must take into account nutrition condition. It is not always the same result under high potassium supply as a certain cultivars behaves better in potassium uptake and utilization under low potassium condition. Difference of dry matter or potassium use efficiency under potassium stress mainly results from the difference of potassium utilization efficiency and not that of potassium uptake efficiency, In contrast, under potassium- sufficient the difference results from uptake efficiency and not that of utilization efficiency. Investigating the absorption, distribution and redistribution of potassium among organs in wheat at pre-anthesis and post-anthesis helps to elucidate the function of potassium o更多还原