钾水平对富士苹果果实膨大期13C同化物向果实转运的影响  

Effects of potassium levels on translocation of 13C-photoassimilates to fruit in‘Fuji’apple during fruit expanding period

作　　者：沙建川 陈倩[1] 王芬[1] 徐新翔 朱占玲[1] 葛顺峰[1] 姜远茂[1] SHA Jian-chuan;CHEN Qian;WANG Fen;XU Xin-xiang;ZHU Zhan-ling;GE Shun-feng;JIANG Yuan-mao(College of Horticulture Science and Engineering,Shandong Agricultural University/State Key Laboratory of Crop Biology,Tai’an 271018,Shan-dong,China)

机构地区：[1]山东农业大学园艺科学与工程学院/作物生物学国家重点实验室,山东泰安271018

出　　处：《应用生态学报》2020年第6期1859-1866,共8页Chinese Journal of Applied Ecology

基　　金：国家重点研发计划项目(2016YFD0201100);国家自然科学基金项目(31501713);国家现代农业产业技术体系项目(CARS-27);山东省泰山学者攀登计划项目资助。

摘　　要：以6年生‘烟富3’/M26/平邑甜茶为试材,采用13C同位素标记技术,在果实膨大期用不同浓度钾素水溶液(K2O浓度分别为0、0.5%、1.0%、1.5%、2.0%,分别用CK、K1、K2、K3、K4表示)涂抹果实周围20 cm范围内叶片,研究其对叶片叶绿素荧光参数、光合性能、糖转运蛋白基因表达、13C同化能力及13C同化物向果实转运的影响。结果表明:与其他处理相比,K3处理显著提高了叶片Rubisco酶活性、净光合速率、PSII原初光能转化效率、PSII实际光化学效率、光化学淬灭系数、山梨醇和蔗糖含量、6-磷酸山梨醇脱氢酶(S6PDH)和蔗糖磷酸合酶(SPS)活性及13C同化能力;提高了果柄组织山梨醇转运蛋白基因MdSOT1、MdSOT2和蔗糖转运蛋白基因MdSUT4的表达,促进了糖在果实中的卸载。13C自留量(自身叶片+自身新梢)以CK最高,为82.6%,K3处理最低,为60.5%。果实13C吸收量随钾素浓度增加呈先升后降趋势,以K3处理最高(1.31 mg·g^-1),CK最低(0.57 mg·g^-1)。表明叶施钾素水溶液不同程度提高了叶片PSII光化学效率和碳同化关键酶活性,进一步提高了叶片同化物的合成能力和向外输送能力,促进了糖向果实的定向转运。同化物向果实转运数量以1.5%K2O涂抹叶片处理(K3)最多。A field experiment was carried out in a six-year old‘Fuji’3/M26/Malus hupehensis Rehd.apple with the 13C tracer method to examine the changes of chlorophyll fluorescence parameters,photosynthetic characteristics of leaf,sugar transporter gene expression,13C assimilation capability and the characteristics of translocation and distribution of 13C-photoassimilates to fruit under different levels of potassium addition(K2O 0,0.5%,1.0%,1.5%,2.0%,expressed by CK,K1,K2,K3,K4,respectively).Potassium aqueous solution smear the leaves within 20 cm around the fruit at fruit enlargement stage.Compared with other treatments,K3 treatment significantly increased Rubisco enzyme activity,net photosynthetic rate,maximal photochemical efficiency of PSII,actual photochemical efficiency of PSII,coefficient of photochemical quenching,sorbitol and sucrose content,sorbitol 6-phosphate dehydrogenase(S6 PDH)and sucrose phosphate synthase(SPS)enzyme activities and 13C assimilation capability of leaves.Furthermore,K3 treatment increased gene expression of sorbitol transporter MdSOT1 and MdSOT2 and sucrose transporter MdSUT4,and promoted the unloading of sugar in fruit.The 13C of self retention(self leaves and self branches)was the highest in CK(82.6%)and the lowest in K3 treatment(60.5%).With increasing potassium concentration,the 13C absorption of fruit first increased and then decreased,which was the highest in K3 treatment(1.31 mg·g-1)and the lowest in CK(0.57 mg·g-1).Our results indicated that foliage application of potassium solution improved PSII photochemical efficiency,activities of key enzymes related with carbon assimilation,synthesis ability,and outward transport ability of photosynthates in leaves,and consequently promoted the directional transportation of sugar to fruit.The amount of photoassimilates transported to fruit was the most under 1.5%K2O treatment(K3).

关 键 词：苹果 钾 13C同化物 转运 果实 

分 类 号：S661.1[农业科学—果树学]