【作者】 辛建华；

【导师】 李天来；

【作者基本信息】 沈阳农业大学 ， 蔬菜学， 2008， 博士

【摘要】 钙是细胞内重要的信号分子,参与植物从种子萌发、生长分化、形态建成,到开花结果的全过程,参与植物的光合电子传递、光合磷酸化、细胞的向性运动和激素调控等,因此,钙是植物生长发育的重要调节因子,对植物的生理活动进行广泛的调节。马铃薯主根吸收的Ca²⁺,主要以蒸腾流的方式输送到植物的各个器官,马铃薯的块茎生长在地下,蒸腾效率很低,所以主根吸收的钙很难直接输送到马铃薯的块茎中去。缺钙会导致马铃薯生长发育中某些生理活动紊乱,引起马铃薯褐斑病、内部空洞和细菌性软腐病等生理性病害,造成马铃薯产量和品质的下降,严重制约了马铃薯产业的快速发展和经济效益的增加。自二十世纪八十年代以来,国外对钙在马铃薯生长发育中的作用做了一些研究,证明外源补施钙肥,可促进主茎增粗,减少块茎形成的数量,增加商品薯产量和块茎内钙的含量,提高块茎的品质,并能延长块茎的贮藏期,减少生理病害的发生。提高块茎中的钙含量最好的方法有两种:一是选育高钙品种,二是增施钙肥。在目前国内的研究中,有关钙肥的施用和钙素在果树生长发育作用,以及钙在逆境胁迫方面的作用研究较多,但关于钙对马铃薯产量和品质的影响及钙在马铃薯生长发育中作用的系统研究尚未见报道。本文利用无土栽培和组织培养的方法,以马铃薯品种费乌瑞它为试材,通过设置不同的钙浓度水平,、研究钙在马铃薯生长发育、干物质积累与分配和块茎形成中的作用,以及钙与光合作用、碳水化合物代谢和激素代谢之间的关系,探讨钙在块茎发育中的作用和生理功能,为马铃薯生产中钙肥的合理施用和优质高产提供理论依据。主要研究结果如下:1通过对紫花白、费乌瑞它、大西洋、布尔班克和诺兰等五个品种的生长发育及钙含量的比较,证明了五个品种的钙含量以紫花白和诺兰较高,分别达到了283.7μg·g^-1DW和255.8μg·g^-1DW,其次是布尔班克为184.8μg·g^-1DW,费乌瑞它和大西洋最低,分别为145.5μg·g^-1DW和144.6μg·g^-1DW,表明品种的钙含量存在着遗传上的差异。2无土栽培法和组织培养法的研究结果不完全一致,随钙水平的提高,无土营养液栽培试验中块茎数量减少,而组织培养试验中块茎数量增加,但块茎的重量、大小、商品率及块茎钙含量,均随钙水平的提高而增加。3通过对两个马铃薯品种（Solanum tuberosum L.）紫花白和费乌瑞它干物质积累和钙含量变化的动态分析,结果表明,两个品种块茎中钙含量的变化趋势相似,即从块茎形成期开始钙含量迅速提高,到块茎膨大结束时降低。在块茎的整个生长发育期间,块茎形成期和膨大期吸收的钙占全部钙含量的60%以上。4明确了随钙水平的提高,马铃薯根、茎叶和块茎中的干物质积累增加。适当的外源钙浓度水平,有助于提高干物质在叶片和块茎中的分配率。随钙水平的提高,块茎中蛋白质、VC和淀粉的含量均有一定幅度的增加,可溶性糖含量,在块茎生长的前期随钙水平的增加而提高,后期下降。5随外源钙素水平的提高,马铃薯叶片的叶绿素a、叶绿素b和类胡萝卜素的含量均有一定程度的增加,缺钙导致叶片光合色素的降低;增加钙浓度水平有利于提高叶片的净光合速率,其变化情况与叶绿素增加的趋势基本一致。缺钙条件下,净光合速率（Pn）、气孔导度（Gs）下降,胞间CO₂浓度（Ci）升高,表明净光合速率的下降是由于非气孔限制因素引起的;但当钙水平达500 mg·L^-1时,净光合速率低于钙水平为300mg·L^-1的处理,气孔导度下降,胞间CO₂浓度也下降,说明钙水平为500 mg·L^-1时,造成光合速率下降的主要原因是气孔限制引起的。最有利于净光合速率提高的钙浓度水平为300 mg·L^-1。缺钙时,F_o、F_v/F_M、F_v/F_o、YIELD和ET均下降,但加钙可使荧光参数上升。随钙处理水平的提高,马铃薯叶片的比叶重增加。6马铃薯叶片的净光合速率日变化呈双峰变化曲线,缺钙导致叶片净光合速率的日变化始终保持在较低的水平,明显低于加钙的处理。当外源钙处理的浓度达300 mg·L^-1时,一天中叶片的光合速率达到了最大值,当钙浓度再提高时,光合速率反而有所下降。缺钙处理的气孔导度（Gs）,胞问CO₂浓度（Ci）,蒸腾速率（Tr）均比加钙处理的要低,说明缺钙导致的光合速率的降低由于气孔限制性因素造成的。增加外源钙浓度水平,可以有效的提高叶片的羧化效率。高钙(300 mg·L^-1和500 mg·L^-1)处理可以有效的提高了马铃薯不同叶位叶片的净光合速率,特别是对上位叶片光合速率的提高更为明显。7适宜Ca²⁺的浓度有利于降低高温胁迫下马铃薯叶片细胞膜的渗漏和MDA含量,显著提高了POD,CAT、SOD以及Ca²⁺-ATP和Mg²⁺-ATP活性,提高马铃薯叶片脯氨酸和可溶性糖的含量。8加钙有利于叶片和块茎中蔗糖和淀粉含量的提高,但降低了葡萄糖和果糖的含量;叶片和块茎中蔗糖磷酸合成酶的活性随钙水平的的提高而增强,而中性转化酶和酸性转化酶的活性却相应的降低;但缺钙处理,蔗糖合成酶活性始终较低,但其转化酶的活性却在各时期都相对较高。10、加钙可以促进叶片和块茎中GA₃、IAA和ZR含量的提高,但却降低了叶片中ABA的含量,提高块茎中ABA的含量。在苗期,钙水平为300和500 mg·L^-1的处理对叶片中GA₃含量的提高效果更为明显,但在块茎中却低于钙水平为75和150 mg·L^-1的处理;从盛花期开始,钙水平为300和500 mg·L^-1的处理,叶片和块茎中GA₃的含量明显下降,含量低于钙水平为75和150 mg·L^-1的处理,块茎中GA₃含量的降低有利于块茎的发生和形成,钙水平为300和500 mg·L^-1处理的块茎中ABA含量高于钙水平为75和150 mg·L^-1的处理,而叶片中却低,表现出较高钙水平处理有抑制叶片衰老和促进块茎形成的作用。更多还原

【Abstract】 Calcium is the important intracellular signal molecule and regulatory factor for the growth and development of plant,which involves in the whole process from seed germination, growth and differentiation,morphogenesis to blossom and bearing;and participates in photosynthetic electron transport and photophosphorylation,cell tropic movement,hormones regulation and so on.Therefore,calcium plays an important role in the physiological and biochemical aspects,and regulates physiological activities of plants broadly.The axial roots of potato absorbed Ca²⁺,which was mainly transported to various orGA3ns of the plant by the transpiration stream.But potato tubers grown under the ground with lower transpiration efficiency,therefore,few Ca²⁺ can be directly transported to the potato tubers.The lack of calcium in potato growth and development would lead to the disorder of some physical activities,and cause physiological diseases such as potato brown spot,internal cavity and bacterial soft rot.Finally,resulting in the decline in yield and quality of potato,seriously restrict the rapid development of the potato industry and increasing of economic benefits. Since the 1980s,foreign studies which were related to the calcium role in the growth and development of potato had a wide range of research,the results showed that increasing application of calcium fertilizer in the process of growth and development of potato could promote stem thickening,reduced the number of stolon and tuber,and increased production of commercial tubers.Meanwhile,it could increase the content of calcium in tubers,improve the quality of tubers,extend the storage period of tubers,and reduce physiological diseases. There are two favorable ways for raising the content of calcium in tubers,that was,1.Breeds high calcium species;2.Increase the application of calcium fertilizer.The current domestic studies related to calcium were more in the development and stress of fruit trees,but the mechanism studies which were related to the impact of calcium on yield and quality of crops were relatively small.The effect of different calcium levels on potato（Solanum tuberosum L.） by the way of using soil less cultivation and tissue culture were studied.For example,the role of calcium in the growth and development of potato,dry matter accumulation and distribution and the formation of tubers;as well as the relationship between photosynthesis,metabolism of carbohydrate and hormone with calcium were studied,the calcium physiological functions and the role of calcium in the development of tubers was discussed.Moreover,a theoretical basis was provided according to the rational application of calcium fertilize in production of potato.The main results were as follows:1 The comparison of growth and calcium content in five species of potato including the Purple White,Favorita,the Atlantic Ocean,Burbank and Nolan,the results showed that the differences of calcium content between the varieties is due to genetic factor.The calcium content of Purple White and Nolan were the highest,which was 283.7μg·g^-1 DW and255.8μg·g^-1 DW respectively;that of Favorita and the Atlantic Ocean were lowest,which was 145.μg·g^-1DW and 144.6μg·g^-1 DW respectively;and that of Burbank was between the above-mentioned varieties,which was 184.8μg·g^-1 DW.2 The results were not the same with soilless culture and tissue culture.With the increasing of the calcium level,the number of tubers decreased for the soilless culture whereas that increased for the tissue culture.However,the weight,size,goods rate and calcium content of tubers increased significantly with two culture methods with the growth of the calcium level.3 The Purple White and Favorita（Solanum tuberosum L.）,two potato varieties,their dry matter accumulation and calcium content were analyzed dynamically.The results showed that the trend of calcium content in tubers of the two species was similar,that was,the content of calcium rapidly raised at the beginning of tuber formation,and declined at the end of tuber expansion.The content of calcium absorbed during the formation and expansion of tubers accounted for 69.5%of that during the whole process of growth and development of tubers. The trend of calcium content in tubers was similar to that of dry weight of tubers.4 The dry matter accumulation of roots,stems,leaves and tubers in potatoes increased with the increasing of calcium level.So appropriate concentration of exogenous calcium could improve the distribution rate of dry matter in the leaves and tubers,but the distribution efficiency of the roots was not obvious.With the growth of calcium level,the content of protein,vitamin C and starch in the tubers increased at a certain rate.The content of soluble suGA3r in the tubers was up at the early growth stage of tuber,and then dropped with the increase of calcium concentration.5 With the increasing of concentration of exogenous calcium,the content of chlorophyll a,chlorophyll b and carotenoid increased to some extent at the various stages of growth and development in potatoes,but calcium deficiency led to the decreasing of photosynthetic pigment.The increasing of the concentration of calcium could be conducive to raise net photosynthesis,and its change trend was similar to that of chlorophyll.Under the conditions of calcium deficiency,the net photosynthetic rate（Pn）,stomatal conductance（Gs） declined and intracellular CO2 concentration（Ci） increased,which showed that the declining of Pn was due to non-stomatal limitation factor.However,the concentration of calcium(500 mg·L^-1) was not favorable to photosynthesis.Pn,Gs and Ci at 500 mg·L^-1 treatment were lower than those at 300 mg·L^-1 treatment,and it was mainly due to Stomata Limitation.Pn at 300 mg·L^-1 treatment was highest.For calcium deficiency,F_o,F_v/F_M,F_v/F_o,YIELD and ET declined,and fluorescence parameters was up when calcium was in abundance.Specific leaf weight（SLW） rose with the increasing of calcium concentration,SLW was smallest at treatment of calcium deficiency(0 mg·L^-1),and the weight was the smallest at calcium deficiency whereas that was largest at high calcium(500 mg·L^-1).6 Diurnal variation of the net photosynthetic in potatoes appeared bimodal curve.The increasing of exogenous calcium appropriately would improve Pn.Under the condition of calcium deficiency,Pn relatively maintained at a low level,and was lower than that at high calcium treatment significantly.When the concentration of calcium was 300 mg·L^-1,diurnal variation of Pn reached a maximum.But the photosynthetic rate declined after the concentration of calcium was more than 300 mg·L^-1.Gs,Ci and Tr at the calcium deficiency treatment were lower than those at the high calcium treatment,which indicated that the declining of Pn was due to stomatal limitation factors.Carboxylation efficiency of the leaves could effectively rise with the increasing of exogenous calcium levels.High calcium treatment(300 mg·L^-1 and 500 mg·L^-1) could effectively improve Pn,especially for the upper leaves,but that was not obvious for the lower leaves.7 Calcium with appropriate concentration could reduce electrolyte leakage rate and the content of MDA in a potato leaf under the heat stress,and significantly raised the activities of enzyme,including POD,CAT,SOD,Ca²⁺-ATP and Mg²⁺-ATP.Content of proline and soluble suger could improve in the leaf of potato.8 At different developmental stages,the content of sucrose in leaves and tubers rose with the increasing of calcium levels,and that at calcium deficiency treatment remained the lowest all the way.In contrast,the content of glucose and fructose dropped with the increasing of calcium levels,and those at calcium deficiency treatment were higher.That was,high calcium level was conducive to improve suger content,but declined that of glucose and fructose. Under the conditions of different calcium levels,the general trend of starch content in the leaves and tubers was 500 mg·L^-1 treatment＞300 mg·L^-1 treatment＞75 mg·L^-1 treatment＞calcium deficiency treatment.9 The activity of sucrose phosphate synthase enhanced with the increasing of calcium levels,and the activities of the neutral-converting enzyme and acid-converting enzyme decreased at the different stages of development of leaves and tubers.Moreover,the activities of sucrose synthase at calcium deficiency treatment remained lower level,but those of converting enzyme were relatively higher.10 Comparing to calcium deficiency treatment,high calcium could improve the content of IAA,GA₃ and ZR in leaves and tubers obviously at different developmental stages of potato,the content of ABA in leaves declined,but ABA content in tubers increased.At the seedling stage,high calcium treatment(300 and 500 mg·L^-1) could increase obviously the GA₃ content in leaves,but lower than that in tubers at low calcium treatment(75 and 150 mg·L^-1);from the beginning of the full flowering period,the GA₃ content in leaves and tubers at high calcium treatment(300 and 500 mg·L^-1) significantly declined,and was lower than that at low calcium treatment(75 and 150 mg·L^-1).The decreasing of the GA₃ content would be favor of tuber formation.The GA₃ content in tubers at high calcium treatment(300 and 500 mg·L^-1) was lower than that at low calcium treatment(75 and 150 mg·L^-1),which was reverse in the leaves.Therefore,appropriate calcium concentration played a role in inhibiting leaves senescence and promoting tuber formation.更多还原