NITROGEN USE EFFICIENCY IN UPLAND RICE GENOTYPES

Nitrogen (N) deficiency is one of the most yield-limiting nutrients in upland rice growing regions word wide. A greenhouse experiment was conducted with the objective to evaluate nineteen upland rice (Oryza sativa. L.) genotypes for N use efficiency. The soil used in the experiment was an Oxisol and two N levels used were without N application (low level) and an application of 400 mg N kg^?1 of soil (high level). Grain yield and yield components and N uptake parameters were significantly affected by N and genotype treatments. Regression analysis showed that plant height, shoot dry weight, number of panicles per pot, number of grains per panicle, grain harvest index, N uptake in shoot and grain were having significant positive relation with grain yield. Nitrogen concentration of 6.4 g kg^?1 in the shoot is established as deficient level and 9.5 g kg^?1 as sufficient level at harvest. Agronomic efficiency of N (grain yield/unit of N applied) and N utilization efficiency (physiological efficiency X apparent recovery efficiency) were significantly different among genotypes. These two N use efficiencies were having significant quadratic relationship with grain yield. Soil pH, exchangeable soil Ca and base saturation were having significantly positive association with grain yield. However, soil extractable phosphorus (P), potassium (K), hydrogen (H⁺), aluminum (Al) and cation exchange capacity were having significantly negative association with grain yield.     

ROOT GROWTH OF UPLAND RICE GENOTYPES AS INFLUENCED BY NITROGEN FERTILIZATION

The plant root system is an important organ which supplies water and nutrients to growing plants. Information is limited on influence of nitrogen fertilization on upland rice root growth. A greenhouse experiment was conducted to evaluate influence of nitrogen (N) fertilization on growth of root system of 20 upland rice genotypes. The N rate used was 0 mg kg^?1(low) and 300 mg kg^?1(high) of soil. Nitrogen X genotype interactions for root length and root dry weight were highly significant (P < 0.01), indicating that differences among genotypes were not consistent at two N rates. Overall, greater root length, root dry weight and tops-roots ration were obtained at an N fertilization rate of 300 mg kg^?1compared with the 0 mg N kg^?1soil. However, genotypes differ significantly in root length, root dry weight and top-root ratio. Nitrogen fertilization produced fine roots and more root hairs compared with absence of N fertilizer treatment. Based on root dry weight efficiency index (RDWEI) for N use efficiency, 70% genotypes were classified as efficient, 15% were classified as moderately efficient and 15% were classified as inefficient. Root dry weight efficiency index trait can be incorporated in upland rice for improving water and nutrient efficiency in favor of higher yields.     

DRY BEAN GENOTYPES EVALUATION FOR GROWTH,YIELD COMPONENTS AND PHOSPHORUS USE EFFICIENCY

Dry bean along with rice is a staple food for the population of South America. In this tropical region beans are grown on Oxisols and phosphorus (P) is one of the most yield limiting factors for dry bean production on these soils. A greenhouse experiment was conducted to evaluate P use efficiency in 20 elite dry bean genotypes grown at deficient (25 mg P kg^?1 soil) and sufficient (200 mg P kg^?1) levels of soil P. Grain yields and yield components were significantly increased with P fertilization and, interspecific genotype differences were observed for yield and yield components. The grain yield efficiency index (GYEI) was having highly significant quadratic association with grain yield. Based on GYEI most P use efficient genotypes were CNFP 8000, CNFP 10035, CNFP10104, CNFC 10410, CNFC 9461, CNFC 10467, CNFP 10109 and CNFP 10076 and most inefficient genotypes were CNFC 10438, CNFP 10120, CNFP 10103, and CNFC 10444. Shoot dry weight, number of pods per plant, 100-grain weights and number of seeds per pod was having significant positive association with grain yield. Hence, grain yield of dry bean can be improved with the improvement of these plant traits by adopting appropriate management practices. Soil pH, extractable P and calcium (Ca) saturation were significantly influenced by P treatments. Based on regression equation, optimum pH value in water was 6.6, optimum P in Mehlich 1 extraction solution was 36 mg kg^?1 and optimum Ca saturation value was 37% for dry maximum bean yield.     

LOWLAND RICE GENOTYPES EVALUATION FOR PHOSPHORUS USE EFFICIENCY

ABSTRACT

Phosphorus (P) deficiency is the most yield-limiting factor in lowland rice production in Inceptisols of Brazil. A greenhouse experiment was conducted to evaluate 12 genotypes of lowland rice (Oryza sativa L.) using an Inceptisol (Typic Haplaquepts). The P treatments were: low (0?mg?P?kg^?1), medium (100?mg?P?kg^?1), and high (400?mg?P?kg^?1). Significant (P<0.01) genotypes differences in P-use efficiency were found. On the basis of P-use efficiency, genotypes were classified as efficient and responsive, efficient and non-responsive, non-efficient and responsive, and non-efficient and non-responsive. From a practical point of view, efficient and responsive and efficient and non-responsive genotypes are the most desirable ones. Among the 12 genotypes tested, none were found to be efficient and responsive and genotypes CNA7553, CNA7591, CNA7601, and Aliança were found to be efficient and non-responsive. Among the yield components, panicle length and harvest index were significantly affected by P levels and genotypes and P and genotypes interactions were significant for these two parameters. However, panicle number was significantly influenced only by P treatment. Among the yield components, panicle number, harvest index, and panicle length were significantly (P<0.01) related to grain yield.     

YIELD AND YIELD COMPONENTS OF UPLAND RICE AS INFLUENCED BY NITROGEN SOURCES

Ammonium sulfate and urea are main sources of nitrogen (N) for annual crop production in developing countries. Two greenhouse experiments were conducted using ammonium sulfate and urea as N sources for upland rice grown on a Brazilian Oxisol. The N rates used were 0, 50, 100, 150, 3000, and 400 kg N kg^?1 of soil. Yield and yield components were significantly increased in a quadratic fashion with increasing N rate. Ammonium sulfate X urea interaction was significant for grain yield, shoot dry matter yield, panicle number, plant height and root dry weight, indicating a different response magnitude of these plant parameters to two sources of N. Based on regression equation, maximum grain yield was achieved with the application of 380 mg N kg^?1 by ammonium sulfate and 271 mg N kg^?1 by urea. Grain yield and yield components were reduced at higher rates of urea (>300 mg kg N) but these plant parameters’ responses to ammonium sulfate at higher rates was constant. In the intermediate N rate range (125 to 275 mg kg^?1), urea was slightly better compared to ammonium sulfate for grain yield. Grain yield was significantly related with plant height, shoot dry weight, panicle number, grain harvest index and root dry weight. Hence, improving these plant characteristics by using appropriate soil and plant management practices can improve upland rice yield.     

Effect of calcium sprays,time of harvest,cold storage,and ripeness on fruit quality of ‘anjou’ pears 1

Calcium chloride (CaCl₂), increased Ca concentrations in fruit cortex and peel of ‘Anjou’ pears (Pyrus communis L.). Calcium sprays reduced the fruit disorders: brown core, cork spot and superficial scald. Fruit size (weight) increased while fruit Ca concentrations decreased with fruit at the later harvest dates. The earliest harvest date was associated with a lower incidence of fruit disorders. Superficial scald increased in fruit held longer in cold storage and in ripened fruit. Shelf‐life and fruit quality of Ca‐sprayed fruit was improved due to higher Ca concentrations in fruit peel and cortex resulting in overall enhancement of fruit appearance, and in improvement in the control of the incidences of cork spot, scald, brown core, and external and internal rots, and in amelioration of fruit juiciness and fruit color.     

Nitrogen-Use Efficiency in Lowland Rice Genotypes under Field Conditions

Rice is staple food for more than 50% of the world's population. Nitrogen (N) is one of the most yield-limiting nutrients for lowland rice production around the world. Two field experiments were conducted at two locations for two consecutive years to evaluate N-use efficiency of 12 lowland rice genotypes. Growth, grain yield, and yield components were significantly influenced by N as well as genotype treatments. Location?×?year?×?genotype and location?×?year?×?N interactions were significant for most of the growth, yield, and yield components, indicating influence of these factors on yield and yield components. Overall, the most N-efficient genotypes measured in terms of grain yield were BRA 031032, BRA 031044, and BRA 02654 and the most inefficient genotypes were BRS Jaçana, BRS Fronteira, and BRA 02674. Genotypes had linear and quadratic responses to added N in the range of 0 to 200 kg ha^?1. Nitrogen significantly influenced plant height, shoot dry weight, panicle number, and 1000-grain weights. Nitrogen-use efficiency (kg grain per kg N applied) varied from 33 to 49 kg grain per kg N applied, with an average value of 40 kg grain per kg N applied. The genotype BRA 031044 produced the greatest N-use efficiency, and the lowest N-use efficient genotype was BRS Fronteira. There was a significant linear association between N-use efficiency and grain yield.     

Comparative Efficiency of Nitrogen Sources for Lowland Rice Production

Rice (Oryza sativa L.) is the staple food for more than 50% world population and nitrogen (N) is one of the most yield-limiting nutrients for rice production worldwide. A greenhouse experiment was conducted to evaluate the efficiency of three N sources for lowland rice production. The N sources used were ammonium sulfate, common urea, and polymer-coated urea. There were three N rates, i.e. 100, 200, and 400 mg N kg^?1 applied with three sources plus one control treatment (0 mg N kg^?1). Growth, yield, and yield components were significantly increased either in a linear or quadratic fashion with the addition of N fertilizers in the range of 0–400 mg kg^?1 soil. Maximum grain yield was obtained with the addition of ammonium sulfate at 100, 200, and 400 mg kg^?1 of soil. Common urea and polymer-coated urea were more or less similar in grain production at 100 and 200 mg N kg^?1. However, at 400 mg N kg^?1 treatments, polymer-coated urea produced the lowest grain yield. Most of the growth and yield components were positively related to grain yield, except spikelet sterility which was negatively related to grain yield. Nitrogen use efficiency decreased with increasing N rate in all the three N sources. Maximum N use efficiency was obtained with the addition of ammonium sulfate at lower as well as at higher N rates compared with other two N sources.     

水稻细胞质雄性不育恢复性的等位基因分化

选用WA型、Y型和DA型3种细胞质的4个不育系(博白A、珍汕97A、协青早A和Y华农A)对6个单片段代换系、8个双片段聚合系和华粳籼74的恢复力进行测交鉴定,结果表明:(1)6个单片段代换系、8个双片段聚合系和华粳籼74对于4个不育系的恢复力存在显著的不同,携带有Rf3基因座位的单片段代换系的恢复力均低于携带有Rf4基因座位的单片段代换系,并且低于对照品种(华粳籼74);单片段代换系S6对这3种不育细胞质均具有较强的恢复力,单片段代换系S5对珍汕97A(WA)、协青早A(DA)具有较强的恢复力。(2)在华粳籼74的遗传背景下,4个不育系可恢复性存在差异,程度依次为:协青早A>博白A>珍汕97A>Y华农A,即Y华农A的不育性最难恢复,而协青早A的不育性最易恢复。(3)在恢复基因Rf3和Rf4基因座分别鉴定出4个等位基因,由弱到强依次命名为Rf31、Rf32、Rf33、Rf34和Rf41、Rf42、Rf43、Rf44,受体亲本华粳籼74的基因型为Rf34Rf34Rf42Rf42,即华粳籼74携带的Rf3基因的恢复性很强,携带的Rf4基因恢复性却比较弱。(4)携带有较弱恢复性基因(Rf3和Rf4)的单片段代换系聚合为双片段聚合系后恢复力有减小的趋势。本研究结果将为水稻三系的选育和恢复基因的转移奠定基础。     

Growth and Zinc Uptake and Use Efficiency in Food Crops

Zinc (Zn) deficiency in annual crops is very common in Brazilian Oxisols. Data are limited on Zn uptake and use efficiency during crop growth cycles. A field experiment was conducted during two consecutive years with the objective to determine shoot dry weight and Zn uptake and use efficiency in upland rice, dry bean, corn, and soybean during growth cycles. Shoot dry weight of four crops was significantly increased in an exponential quadratic fashion with increasing plant age. Rice and corn had higher shoot dry weights and grain yields than dry bean and soybean. Zinc concentration in rice and corn decreased in a quadratic fashion with increasing plant age. However, in dry bean and soybean, Zn concentration had a quadratic increase. Zinc uptake followed an exponential quadratic response in four crops, and it was higher in corn and upland rice than in dry bean and soybean. Zinc use efficiency in shoot dry‐weight production had significant quadratic responses in upland rice and soybean with increasing plant age. In corn, Zn use efficiency for shoot dry‐weight production was linear as a function of plant age. Zinc use efficiency for grain production was maximum for corn and minimum for soybean. Hence, cereals had higher Zn use efficiency than legumes.

Zinc concentration in grain of dry bean and soybean was higher than in upland rice and corn, which is a desirable quality factor for human consumption so as to avoid Zn deficiency.     

高产抗病早籼品种辐501的选育

辐501是以早籼中间材料Z96-12为母本、Z95-03为父本杂交,F1代干种子经过80Gy60Coγ射线,M6F6代干种子经过300Gy60Coγ射线2次辐照处理,采用系谱法育成的一个早籼常规品种。该品种表现丰产性和稳产性较好,生育期适中,抗稻瘟病和适应性广等特性,并于2011年2月通过浙江省农作物品种审定委员会审定。     

Agronomic Evaluation of Coated and Common Urea in Upland Rice Production

Two greenhouse experiments were conducted simultaneously to evaluate polymer-coated and common urea in upland rice production. The nitrogen (N) levels used for both the N sources were from 0 to 400 mg kg^?1 of soil. Maximum grain yield was obtained with the addition of 167 mg N kg^?1 polymer-coated urea and 238 mg N kg^?1 common urea. Maximum value of other plant traits was obtained with N applied from 233 to 313 mg kg^?1 depending on plant traits and N source. Nitrogen-use efficiency (NUE) decreased with increasing N rate in the two N sources. Based on results of growth, yield, and yield components, and NUE it can be concluded that the N sources were equally effective in upland rice production. Base saturation, pH, and exchangeable calcium (Ca) increased with increasing N rates while iron (Fe), manganese (Mn), and copper (Cu) contents decreased with the increasing N rates.     

GENETIC ANALYSIS AND GENE FINE MAPPING FOR MUTATION OF YELLOW-GREEN LEAF IN RICE

通过甲基磺酸乙酯（EMS）诱变晚粳稻品种秀水09,获得了1个稳定遗传的全生育期黄绿叶突变体Ygl,遗传分析表明该突变性状由1对隐性核基因控制。利用突变体与籼稻品种珍汕97杂交,构建F2群体对突变基因进行定位,发现目的基因与第11号染色体上的SSR标记RM2459连锁,在该标记附近发展了14对InDel标记,将突变基因定位在约82kb区间内。通过在线最新水稻注释系统的基因功能预测分析,寻找候选基因,经测序发现突变体发生单碱基突变。