【作者】 张文杰；

【导师】 杨建昌；

【作者基本信息】 扬州大学 ， 作物栽培学与耕作学， 2006， 硕士

【摘要】 本研究试图阐明水稻根系化学讯号(激素、多胺和有机酸等)与米质形成的关系。试验以不同基因型水稻品种为材料,分别种植于水培池、盆钵和大田,观察并分析了根系化学讯号与稻米品质的关系,探讨了调节根系讯号产生和改善稻米品质的技术途径。主要结果如下:1.根系玉米素+玉米素核苷(Z+ZR)浓度与胚乳细胞增殖速率呈极显著正相关(r = 0.88**),而根系异戊烯基腺嘌呤+异戊烯基核苷(iP+iPA)浓度与胚乳细胞增殖速率相关不显著(r = 0.33)。在抽穗始期用10-7 mol L-1 ZR处理根系,根系伤流液中的Z + ZR含量以及强、弱势粒的胚乳细胞数均较对照显著极显著增加。用10-7 mol L-1 iPA处理根系,根系伤流液中的iP + iPA含量以及强、弱势粒的胚乳细胞数与对照差异均不显著。表明根系Z+ZR对胚乳细胞的发育有调控作用。2.灌浆中、后期根中Z+ZR浓度与胶稠度及碱化值呈显著或极显著正相关(r=0.72*～0.90**),与直链淀粉含量呈显著或极显著负相关(r=-0.68*～- 0.78**);灌浆中期根中脱落酸(ABA)浓度与胶稠度及碱化值呈极显著负相关(r=-0.90**～-0.91**),与直链淀粉含量呈极显著正相关(r=0.87**);灌浆各期根中Z+ZR或ABA浓度与稻米的外观品质指标(透明度、垩白米率和垩白度)的相关均不显著。花后0～6 d和14～20 dZR处理、以及花后0～6 d和24～30 d的ABA处理,对稻米的蒸煮品质无显著影响;花后根系14～20 d外源ABA处理后,直链淀粉含量增加,碱化值减小,米胶长度缩短;花后24～30 d外源ZR处理则显著降低了直链淀粉含量,增加了碱化值和米胶长度。3.灌浆中后期根系1-氨基环丙烷1-羧酸(ACC)浓度与垩白粒率和垩白度呈极显著正相关(r = 0.97**～0.98**)。灌浆前期根系ACC浓度与垩白粒率、垩白度和米粒的垩白大小以及灌浆各期根系ACC浓度与稻米的胶稠度、碱化值和直链淀粉含量的相关均不显著。在花后10～15 d和花后25～30 d分别用10-6 mol·L-1 ACC处理根系,稻米的垩白粒率、垩白大小和垩白度均显著增加。用10-6 mol·L-1 AVG (氨基-乙氧基乙烯基甘氨酸,ACC合成酶抑制剂)处理根系,结果则相反。4.根系分泌的苹果酸及琥珀酸浓度与淀粉谱的崩解值呈极显著的正相关(r = 0.95**～0.97**),与淀粉谱的消减值呈极显著的负相关(r =-0.96**～-0.97**);根系分泌的酒石酸和柠檬酸浓度与淀粉谱的崩解值呈极显著的负相关(r = -0.94**～-0.95**),与淀粉谱的消减值呈极显著的正相关(r =0.95**～0.97**);根系分泌的乳酸浓度与稻米胶稠度和碱化值呈显著负相关(r = -0.76*～-0.78**),与直链淀粉含量呈显著正相关(r = 0.81*)。根系分泌的有机酸浓度与其它稻米品质指标的相关均不显著。5.根系分泌物中乳酸浓度较高的品种,根系和稻株吸收隔(Cd)的量较低;而根系分泌苹果酸和琥珀酸浓度较高的品种,根系和稻株对铅(Pb)的吸收量较低。在基肥中用菜籽饼作有机肥,根系分泌的苹果酸和琥珀酸浓度增加,酒石酸和柠檬酸浓度降低,乳酸的浓度无显著变化,稻米淀粉谱的崩解值增大,消解值减小。6.根系精胺浓度与稻米醇溶蛋白呈极显著负相关(r=-0.85**),与球蛋白呈显著正相关(r = 0.67*);根系腐胺浓度与稻米醇溶蛋白呈极显著正相关(r = 0.84**),与球蛋白呈显著负相关(r =-0.87**);根系精胺/腐胺浓度比值与醇溶蛋白呈极显著负相关(r = -0.95**),与球蛋白呈极显著正相关(r = 0.90**)。上述结果表明,根系化学讯号与稻米品质有密切的关系。通过遗传改良、栽培和化控等措施调节水稻根系化学讯号,可以改善稻米品质。更多还原

【Abstract】 This study was designed to elucidate the relationship between the root chemical signals (hormones, polyamines and organic acids) and the grain quality of rice. Various rice genotypes were used. The experiments were conducted in the paddy field, water-culture pools and in pots. The relationship between root chemical signals and the grain quality was studied, and the techniques to regulate root chemical signals and improve grain quality were investigated. The main results are as follows:1. Concentrations of zeatin (Z) + zeatin riboside (ZR) in roots were very significantly and positively correlated, whereas those of N6-isopentenyladenine (iP) + N6-isopentenyladenosine (iPA) were not significantly correlated, with the proliferation rates of endosperm cells, with r=0.88** and r=0.33, respectively. When roots were treated with 10-7 mol L-1 ZR at the early grain filling satge,the number of endosperm cells in both superior and inferior grains was significantly or very significantly increased, but the number was not significantly increased when roots were treated with 10-7 mol L-1 iPA, indicating that the endosperm development is regulated by Z+ZR levels in rice roots.2. Concentrations of Z+ZR in the roots at mid and late grain filling stages were significantly and positively correlated with the gel consistency and alkali spreading value (r=0.72* ~ 0.90**), whereas negatively correlated with the amylose content (r=-0.68* ~ -0.78**). Abscisic acid (ABA) concentrations in roots at mid grain filling stage were significantly and negatively correlated with gel consistency and alkali spreading value (r=-0.90** ~ -0.91**), and positively correlated with the amylose content (r=0.87**). Z+ZR or ABA concentrations at all the filling stages were not significantly correlated with rice appearance quality indexes (transparency, chalky kernel and chalkiness). The effects of ZR treatments at 0~6 and 14~20 DAA and ABA treatments at 0~6 and 24~30 DAA on cooking quality of rice were not significant. The amylose content increased, whereas the alkali spreading value and gel consistency were reduced when exogenous ABA was applied at 14~20d after anthesis. In contrast, the amylose content was reduced, whereas the alkali spreading value and gel consistency were increased when exogenous ZR was treated at 24~30 DAA.3. Concentrations of 1-aminocylopropane -1-carboxylic acid (ACC) in root exudates at mid grain filling stage were very significantly correlated with the percentage of chalky grains and chalkiness (r = 0.97**~ 0.98**), and those at late grain filling stage were significantly correlated with chalkiness and chalky size (r = 0.69*~ 0.96**). ACC concentrations in roots at early grain filling stage were not significantly correlated with the percentage of chalky grains, chalkiness and chalky size, and neither were significantly correlated between ACC concentrations and gel consistency, alkali spreading value and amylose content at each grain filling stage. The percentage of chalky grains, chalkiness and chalky size of rice were all significantly increased when rice roots were treated with 10-6 mol·L-1 ACC at 10~15 or 25~30 DAA. The results were reversed when 10-6 mol·L-1 amino-ethoxyvinylglycine, an inhibitor of ACC synthetase, was applied.4. Concentrations of malic acid and succinic acid secreted by roots were significantly and positively correlated with the breakdown value in starch-profile (r = 0.95**～0.97**), whereas negatively correlated with the setback value (r =-0.96**～-0.97**). The concentrations of tartaric acid and citric acid secreted by roots were significantly and negatively correlated with the breakdown value in starch-profile (r =-0.94**～-0.95**), whereas positively correlated with the setback value (r =-0.95**～-0.97**), the concentrations of lactic acid secreted by roots were significantly and negatively correlated with rice gel consistency and alkali spreading value (r = -0.76*～-0.78**), whereas positively correlated with amylose content (r = 0.81*). The concentrations of organic acids secreted by roots were not significantly correlated with other rice quality indexes.5. The root and plant obsorbed less amount of cadmium (Cd) for a cultivar with more lactic acid in root exudates, whereras obsorbed more amount of lead (Pb) for a cultivar with more the malic acid and succinic acid exuded from the roots. When rape cake was used as organic fertilizer in the basic fertilizers, the concentrations of malic acid and succinic acid in root exudates were increased, while the concentrations of tartaric acid and citric acid were decreased, and no significant changes in lactic acid were observed. Application of rape cake increased the breakdown value whereas reduced the setback value in starch-profile.6. Concentrations of spermine in rice roots were very significantly and negatively correlated with prolamine content in the grain (r = -0.85**), whereas significantly and positively correlated with the content of the globulin (r = 0.67*). The concentrations of putrescine secreted by roots were very significantly and positively correlated with prolamine content in grains (r = 0.84**),but significantly and negatively correlated with the globulin content (r =-0.87**). The ratio of spermine to putrescine (spermine/ putrescine) in roots was very significantly and negatively correlated with the content of the prolamine (r = -0.95**) and significantly and positively correlated with globulin (r = 0.90**).The results suggest that root chemical signals are closely associated with the grain quality of rice, and that the root chemical signals would be regulated and the grain quality of rice be improved via genetic improvement or chemical controlling or cultivation techniques.更多还原