【作者】 张蓉；

【导师】 黄丽芬；

【作者基本信息】 扬州大学 ， 生态学， 2015， 硕士

【摘要】 近年来,有机稻米因其健康安全在中国迅猛发展且潜力巨大,但有机栽培下关键营养元素氮素吸收利用特点的研究尚缺乏系统性。本研究于2013、2014年度在江苏高邮市有机稻米生产基地进行田间试验,设置了不施(0)、低量(LO)、中量(MO)、高量(HO)有机肥4个有机栽培(OF)施肥模式和1个常规栽培(CF)施肥模式,以32个长江下游地区推广种植的生育期相近、在常规栽培下氮素利用效率差异显著的常规粳稻品种为材料,研究了在两种栽培体系下产量和氮素利用效率,分析了不同栽培条件下氮素利用效率协同、转变及其机理,为有机水稻生产品种选择及养分管理提供科学依据。主要研究结果如下：1.随着有机肥施用量增加,各水稻基因型间的产量差异有减小的趋势。32个水稻品种获得最高生产力所对应的施氮量也有所不同,主要集中在中量和高量有机肥水平处理。有机栽培群体最高生产力变幅为5.31-8.45 t·hm-2,品种间的变异系数达10.96%根据最高生产力,将有机栽培模式下的产量分为3个等级：高层水平(HY,最高籽粒产量>6.75 t·hm-2)、中层水平(MY,6.0t·hm-2≤最高籽粒产量≤6.75 t·hm-2)和低层水平(LY,最高籽粒产量<6.0t·hm-2)。有机水稻氮素利用效率变幅为12.12%-35.36%,随着有机肥施用量的增加呈现先上升后下降的趋势,在中量有机肥处理下最高。基于群体最高产量及相应的氮素利用效率,将有机栽培下水稻品种进行了分类。2.常规栽培模式下各水稻基因型氮素利用效率变幅为31.44%-45.83%。比较有机和常规两种栽培体系氮素吸收利用效率,将水稻品种分成4种类型：有机与常规栽培均高效(高效协同型,A类)；有机栽培高效而常规栽培低效(高-低转变型,B类)；有机栽培低效而常规栽培高效(低-高转变型,C类)；有机栽培与常规栽培均低效(低效协同型,D类)。3.在A、B、C、D四类品种中分别选取了镇稻15、南粳46、淮稻5号、苏香粳4个代表性基因型,在水稻孕穗期-成熟期,测定了4类水稻基因型在有机与常规模式下剑叶氮素、生理活性指标。B类基因型在有机栽培条件下剑叶含氮率较高,SPAD值和剑叶含氮率下降较慢,而C类型则在常规栽培下下降较小。有机栽培下C、D两种类型剑叶含氮量下降幅度均大于常规栽培。有机栽培下A、B两种类型剑叶GS活性下降幅度小于常规栽培,而C、D两种水稻类型均大于常规栽培。栽培方式对水稻剑叶GPT、GOT活性的影响趋势与GS基本相似。表明有机栽培模式能减缓高产氮高效品种(A、B)氮代谢酶活性的下降速率,维持水稻生育后期相对较高的氮素吸收利用能力。同时,有机栽培方式较常规栽培能减缓A、B类品种生育后期SOD活性的下降速率和MDA含量上升速率,延缓叶片的衰老,而加快了C、D类品种叶片衰老速度。与其他品种相比,有机栽培方式显著改善了B类品种的外观品质、食味性、RVA谱特征值,提高了P、K、Ca、Mg等中量元素和Cu、Mn、Zn、B等微量元素的含量。更多还原

【Abstract】 In rencent years, organic rice, being a healthy and safe organic food, has developed rapidly and had huge market potential in China. However, the mechanism of nitrogen absorption in organic rice is still currentlly unknown. To investigate this issue, in 2013 and 2014, this study was conducted in an organic farm in Gaoyou city, Jiangsu province. Thirty-two selected conventional representative Japonica rice varieties, with similar growth stage and various nitrogen use efficiency (NUE) under conventional farming were field-grown. Four treatments of organic farming (OF), including CK, three (low, medium and high) levels of organic fertilizer (designated LO, MO and HO respectively), and conventional farming (CF,270 kg-hm"2) were conducted from all the growth period of rice. Through this study, special germplasm resources of organic rice with high NUE will be screened. The NUE mechanism of organic rice will also provide a scientific basis for organic rice cultivation, selection of species and nutrient management. The main results were as follows:1. With the increase levels of organic fertilizer, the differences between yields of various rice genotypes have a decreasing trend. The corresponding treatment of organic fertilizer level, under which achieving the maximum productivity for 32 rice varieties, is also different. Most genotypes maintained their maximum productivity under treatments of middle and high levels of organic fertilizer. Under organic farming, the maximum productivity ranged from 5.31 to 8.45 t·hm-2, the coefficient of variation between varieties was 10.96%. According to the highest productivity under OF, all the varieties could be classified as three levels:the top level (HY, the highest grain yield> 6.75 t·hm-2), the middle level (MY.6.0 t·hm-2≤ highest grain yield≤6.75 t·hm-2) and the low level (LY, the highest grain yield<6.0 t·hm-2). Nitrogen use efficiency of organic rice ranged from 12.12% to 35.36%. With the increase of organic fertilizer application, nitrogen use efficiency firstly increased and then decreased, maintaining the highest NUE at treatment of middle-level organic fertilizer. Based on the highest yield and the corresponding NUE, the rice varieties were classified under organic cultivation.2. Under conventional farming, NUE of various rice genotypes ranged from 31.44% to 45.83%. After comparison the difference of NUE between OF and CF, the 32 genotypes of rice could be classified as four types:with high NUE under both organic and conventional farming (synergistically high NUE type, A-type); with high NUE under OF and low NUE under CF (high-low NUE transition type, B-type); with low NUE under OF and high NUE under CF (low-high NUE transition type, C-type); with low NUE under both organic and conventional farming (synergistically low NUE type, D-type).3. Among four types of representative rice, Zhendao 15, Nanjing 46, Huaidao 5 and Suxiangjing 1 were selected as representative genotypes as types A, B, C and D respectively. From booting to maturity stage, physiological activity of flag leaves of those four rice genotypes under organic and conventional farming. Under OF, high value of SPAD and nitrogen content, decreasing slowly during the growth period, were observed in B-type genotypes rice. Whereas, under CF, those indexes decreased slowly in C-type. The magnitude of decline in nitrogen content of C-type and D-type was bigger under OF than that under CF. As for GS activity of flag leaf, the decline magnitudes of A-type and B-type were smaller under OF than those under CF. Whereas, C-type and D-type had the opposite trends. The influences of cultivation patterns on the GPT, GOT activities in flag leaves were similar as GS activities. So it demonstrated that organic farming could slow the decline rate of key nitrogen metabolism enzyme activity in A-type and B-type, thus maintaining relatively high capacity of nitrogen uptake and utilization during the late growth period of rice. Moreover, organic farming could increase the content of SOD and decrease the content of MDA in A-type and B-type and delay leaf senescence. On the contrary, OF speeded up leaf senescence of C-type and D-type. Compared with the other genotypes, organic farming significantly improved the appearance quality, the rice palatability, RVA characteristics and the content of P, K, Ca, Mg, Fe, Mn, Zn, B, etc in B-type rice.更多还原