【作者】 万吉丽；

【导师】 王人民；

【作者基本信息】 浙江大学 ， 作物学， 2010， 硕士

【摘要】 水稻是人类的主要粮食作物之一,稻米中的锌含量、分布及其生物活性,对以稻米为主食的人口的锌营养至关重要,然而锌在稻米中的分配与积累机制尚不明确。本试验选用籽粒锌含量有差异的不同基因型水稻,研究了不同供锌水平对水稻生长发育及产量和品质的影响,研究了不同时期不同基因型水稻对锌吸收、分配和积累的动态变化规律,得到以下结论:1、在缺锌pZn²⁺11.4条件下,相对于锌敏感基因型IR26,耐低锌基因型IR8192能够更有效地增加干物质在地下部的分配来增加根长、扩大吸收面积,从而更有效地应对低锌胁迫。2、水稻叶片叶绿素含量、胞间CO₂浓度、光合速率均随着锌离子活度升高而升高。严重缺锌使水稻蒸腾速率下降显著,当锌离子活度大于pZn²⁺11.0时,锌离子活度再升高,蒸腾速率的变化不显著。各基因型的气孔导度均在pZn²⁺ 9.7时达到最大。3、苗期和分蘖期,水稻叶片中的锌,主要以活性较低的醋酸提取态（重金属磷酸盐）存在;拔节至抽穗期,锌主要以乙醇提取态（醇溶性蛋白、氨基酸等）存在。4、锌离子活度通过对水稻有效穗数、每穗颖花数、结实率和千粒重的影响而显著影响水稻单株产量,其中影响最大的是单株有效穗数,其次是每穗颖花数,而对结实率的影响相对较小,但均存在明显的基因型差异。5、碧玉早糯（BY）和浙农921（Z921）各器官的锌含量都随着锌离子活度的升高而增加,但不同基因型间,同一基因型不同器官间均存在差异。较高锌离子活度pZn²⁺10.3和pZn²⁺ 9.7下,锌首先向茎、叶等营养器官分配;缺锌pZn²⁺ 11.0和pZn²⁺ 11.4条件下,锌首先满足籽粒的需要。从籽粒锌分配看,当锌离子活度小于pZn²⁺10.3时,糙米锌含量最高,当pZn²⁺ 9.7时,颖壳锌含量则超过糙米的锌含量。糙米和精米锌含量的比值在0.79-0.90之间变化,并以pZn²⁺ 9.7时为最小。各种锌离子活度下,BY籽粒锌含量均大于Z921。6、水稻种子本身的锌含量增加,能显著提高种子发芽率、发芽指数和活力指数。种子锌含量增加,对第8 d幼苗生长起促进作用,对第14 d幼苗生长的促进作用不明显。种子锌含量增加使幼苗叶绿素含量明显增加。7、种子锌含量与幼苗脯氨酸、MDA含量呈线性负相关,与可溶性糖和可溶性蛋白含量呈线性正相关。种子本身锌含量的增加有助于幼苗POD、CAT和APX酶活性的增强,以此来抵制活性氧、清除自由基等有害物质,更好的起到保护细胞不受伤害的作用。说明水稻种子本身锌含量的增加有利于增强幼苗的渗透调节能力,从而提高其应对逆境胁迫的能力。更多还原

【Abstract】 Rice is one of the major food crops for human,Zn content,distribution and biological activity of rice is essential for rice-eating humans zinc nutrition.However, the systems of Zn partitioning and accumulation is not perfect.In this study,different rice genotypes with different Zn contents were used.This research focus on rice agronomic characteristics,yield,quilty,zinc partitioning and accumulation to different Zn2+ activities.The results were as follows:1.The study showed that under deficiency condition pZn²⁺ 11.4,zinc-efficient genotype IR8192 could more effectively increase dry matter of root,to increase root length and root absorbing area,so as to more effectively deal with the low zinc stress than zinc-inefficient genotype IR26.2.Chlorophyll content,intercellular CO₂ concentration,photosynthetic rate were increased with the increasing Zn²⁺ activities.Extremely zinc deficiency made transpiration rate of seedling rice significantly decreased,when Zn²⁺ activities higher than pZn²⁺ 11.0,the further increase of Zn²⁺ activities could not make transpiration rate change significantly.Stomatal conductance of all genotypes were maximum at pZn²⁺ 9.7.3.In the seedling and tillering stages,acetic acid-extractable（heavy metal phosphates） zinc predominated in the leaves;jointing to heading stages, ethanol-extractable（alcohol-soluble proteins,amino acids,et al） zinc predominated in the leaves.4.Different Zn²⁺ activities had a significant effect on rice yield per plant through effective panicles per plant,spikelet numbers per panicles,seed setting rate, 1000-grain weight.Effective panicles per plant was mostly affected,spikelet numbers per panicles less,the effect on seed setting rate was relatively little, but it was differed between BY and Z921.5.The zinc content was increased in every organs with the decreasing of Zn²⁺ activity,and there were differences between genotypes,also organs.Zn first accumulated to vegetative organs under sufficient Zn supply;Zn first accumulated to grains under deficient Zn supply.Judging form the distribution of grain zinc,when Zn²⁺ activity lower than pZn²⁺ 10.3,the zinc content in brown rice was higher than that in grain hull,but with the Zn²⁺ activity increasing,the zinc content in grain hull became higher.The zinc ratio of brown rice to milled rice was always between 0.79 to 0.90,the ratio was the smallest when pZn²⁺ 9.7.The grain zinc content in BY was much higher than that in Z921 at any Zn2+ activity.6.The seeds germination rate,germination index and vigor index increased with the Zn content of rice seeds increasing.The seedling height and root length of the 8th rice seedling increased with the Zn content of rice seeds increasing. The seedling chlorophyll content increased significantly with the Zn content of rice seeds increasing.7.Seedling protein and MDA content was negatively correlated with Zn content of rice seeds;soluble sugar and soluble protein was positively correlated with Zn content of rice seeds.APX,POD,CAT activity increased certainly with the Zn content of rice seeds increasing,in order to resist the reactive oxygen species,scavenging free radicals and other harmful substances,and better to protect cells from damage.So,increasing Zn content of rice seeds was conducive to enhancing the seedling osmotic adjustment ability in order to improve their ability to cope with stress.更多还原