【作者】 卞芬茹；

【导师】 马文奇；

【作者基本信息】 河北农业大学 ， 植物营养学， 2008， 硕士

【摘要】 植酸是谷物种子磷的主要贮存形式,植酸磷占种子中总磷的60～80%,单胃动物由于缺乏分解植酸磷的酶而不能有效吸收利用植酸磷,这部分磷以粪便形式排出体外,造成严重的粪磷污染。玉米作为最重要的饲料作物,降低玉米籽粒中植酸磷含量对减少粪磷污染有重要意义。目前研究以低植酸突变体居多,本文在比较玉米不同品种籽粒中植酸磷含量特点基础上,探讨玉米籽粒植酸磷、无机磷、总磷的积累规律及其磷形态特征,着重研究了供磷水平、供氮水平、基因型、农艺性状等因素对玉米籽粒植酸磷含量和积累的影响。结果表明:1.从50个自交系与24个杂交种的结果看,50个自交系植酸磷含量平均为1.97 mg/g,其中最低为1.33 mg/g,与最高值2.67 mg/g,相差一倍;24个杂交种植酸磷含量范围在1.50～2.30 mg/g间,平均含量为1.81 mg/g。表明不同基因型玉米籽粒植酸磷、无机磷、总磷含量存在比较大的差异,并且也存在植酸磷含量相对较低和无机磷相对较高的材料,说明从现有玉米自交系和杂交种中进行低植酸磷和高无机磷材料的筛选是可行的。从50份骨干自交系中选择出丹黄02植酸磷含量较低、无机磷含量高、农艺性状较为优异的自交系。2.通过对24个杂交种和50份自交系植酸磷、无机磷、总磷的相关性分析得,无机磷和植酸磷之间呈弱度正相关,因此,单独利用植酸磷或无机磷都很难保证获得植酸磷含量较低、无机磷含量较高的材料,本文建议应该同时利用这两个指标。3.玉米籽粒形成初期,并不含有植酸磷,随着籽粒的生长,植酸磷含量和积累量不断增加,增长趋势大致分为快—慢—快—慢四个阶段。无机磷含量随着籽粒形成不断下降;积累量在前期呈增长趋势,后期两品种变化趋势不同,金海5呈下降趋势,而浚单20基本上保持平稳。总磷含量的变幅不大,整个生育期呈稳中略降状态;总磷积累量前期呈直线增加,后期在平稳中略有上升。在玉米籽粒发育过程中,植酸磷、无机磷、总磷间有较好的交互作用。4.金海5和浚单20玉米籽粒的整个生育期,提高供磷水平显著增加了玉米籽粒中植酸磷和总磷的含量,而无机磷含量并未增加。5.对174个自交系和两个亲本分析表明,植酸磷、总磷、氮三者的含量之间均呈极显著的正相关关系,表明三者间有较好的交互作用。提高供氮水平降低了玉米籽粒中植酸磷含量;高氮水平下植酸磷浓度的平均值为1.90mg/g,分布在1.15～2.51mg/g间;低氮水平下植酸磷浓度平均值为2.34mg/g,分布在1.68～3.07mg/g间;不同自交系植酸磷含量受氮素影响的基因型差异较大,供试的174个自交系中,高氮水平比低氮水平植酸磷含量最多升高了0.20mg/g,最多降低了1.11mg/g。低氮水平比高氮水平植酸磷含量平均高0.44mg/g,增长了23%。但总磷含量不同基因型间受供氮水平影响的差别很大,所测174个自交系,随供氮水平升高总磷含量增加和降低的品种基本各占一半。6.对玉米籽粒中植酸磷含量与株高、穗粗和穗行的相关性分析结果表明,玉米籽粒中植酸磷含量与株高、穗粗和穗行的相关性不大。更多还原

【Abstract】 Phytic acid is the primary storage form of phosphorus (P) in cereal grains and phytic acid P accounts for 60~80% of total P in the seeds. Phytic acid P is indigestible for non-ruminant livestocks, for lack of phytase, and it would expel from the stomach with the excrement, resulting in serious P-pollution. The maize qua one important component of the feedstuff, for that reducing the phytic acid P content is significant to decrease the P-pollution. Most of the latest studies are about the low-phytic-acid mutants. Based on the field experiments, this paper compares the characters in seed phytic acid P content with the different maize genotypes, explores the accumulation model of phytic acid P during seed filling, and studies the relationships of P supply, N supply and some agriculture characters to phytic acid P content and accumulation in the maize seeds. The results showed as follows:1. The results of testing phytic acid P content of 50 inbred lines and 24 hybrid seeds showed that, the mean of phytic acid P content in 50 inbred lines was 1.97mg/g, there was the minimum 1.33 mg/g and the maximum 2.67mg/g among them, and the maximum was two times of the minimum. The mean of phytic acid P content in 24 hybrid seeds was 1.81mg/g(1.50~2.30mg/g). This showed that there were significant differences in inorganic P, phytic acid P and total P among different genotypes and there were the material which was the relatively high and low phytic acid P content, which was saying that it was possible that we could find the material of low phytic acid P and high inorganic P from the existing inbred lines and hybrids. Danhuang02 was an inbred line with low phytic acid P, high inorganic P content and excellent agriculture character.2. The result of the relativity of phytic acid P , inorganic P and total P of 50 inbred lines and 24 hybrid seeds showed that phytic acid P and inorganic P are not significant positive correlation. So it is suggested that we should use two indexes (phytic acid P and inorganic P) to select the ideal genotype, because it will be difficult to find the material which is low phytic acid P and high inorganic P solely by using one index.3. There wasn’t phytic acid P when the maize seeds begin to develop, but as it was developing, phytic acid P content and accumulation amount increased constantly. The increasing model could be divided into four periods for rapidness-slow- rapidness-slow. Inorganic P content descended constantly with the seeds developing, its accumulation amounts increased in the early, at the late stage, Jinhai5 descended, while Xundan20 kept steady basically. The difference of total P content during seed development was little, and it was steady with slight decline as the whole growth and development period, its accumulation amount increased quickly early while slowly in the late. In the whole developed course, there were well interaction among phytic acid P, inorganic P, total P and weight per hundred seeds.4. In the whole developed of Jinhai 5 and Xundan 20,increasing the P supply rised phytic acid P and total P content significantly. While inorganic P didn’t enhance at high P supply.5. The results for the analysis of 174 inbred lines and 2 parents showed as follows, there were significant positive correlation among phytic acid P, inorganic P and total P content, which show that they had well interaction. Increasing N supply could promote phytic acid P content, the mean of phytic acid P was 1.90mg/g at low N supply, distributed between 1.15 mg/g and 2.51 mg/g; the mean of phytic acid P was 2.34mg/g at low N supply, distributed between 1.68 mg/g and 3.07 mg/g. The influnce of different maize breeds’ phytic acid P content was diverse. Among 174 inbred lines for test material, phytic acid P conten at high N supply was most reduced 0.29mg/g than low N supply, however, the most incremental value was 1.11mg/g,phytic acid P content at low N supply was higher 0.44mg/g than low N supply, which rised 23%.There are great diversity of influnce of N supply about different genotypes maize.The inverse proportion about the genotypes which increasing and depressing with rising N supply among 174 inbred lines.6.The correlation analysis of phytic acid P content in the seed of maize,plant height,ear thick and ear row showed that the correlation were not significant between phytic acid P content and plant height,ear thick and ear row,respectively.更多还原