QTL analysis of leaf photosynthetic rate and related physiological traits in rice(Oryza sativa L.)

Photosynthesis is one of the most important factors that influence the biomass and yield. Recently, more attention has been paid to genetic study on rice photosynthesis and rice breeding for the physiological traits related to high efficient photosynthesis. Chlorophyll content, stomatal resistance, and transpiration rate were very important physiological traits related to photosynthesis. But until now, no genetic study on these traits has been reported. A DH population derived from anther culture of ZYQ8/JX17, a typical indica/japonica hybrid was developed,

Analysis of variation in temperature-responsive leaf color mutant lines induced from Gamma irradiation in rice(Oryza sativa L.)

Eight lines of temperature-responsive leaf colormutants induced by applying 300 Gy Gamma-ray irradiation to Thermo-sensitive genic malesterile line 2177s,were obtained through con-tinuous selection in seven generations..Theleaves of these lines started to become greenafter the fourth leaf extension,and except

Soil boron fertilization:The role of nutrient sources and rootstocks in citrus production

Boron （B） is a key element for citrus production, especially in tropical regions, where the nutrient availability is commonly low in the soil. In addition, information about doses, fertilizer sources, methods of application, and particularly, differential nutrient demand of scion/rootstock combinations are required for efficient fertilization of commercial groves. In a non-irri- gated sweet orange orchard （cv. Natal）, grafted onto Rangpur lime, Swingle citrumelo or Sunki mandarin, we studied the application of two sources of B： boric acid （17% B, soluble in water） and ulexite （12% B, partiaJly soluble in water） at four levels of supply （control without B, and soil application of 2, 4 and 6 kg ha-1 yr-1 of B）. The experiment was carried out for three years （2004-2006）. Boron availability in the soil and concentration in the leaves, as well as the fruit yield and quality of trees were evaluated. Soil B extracted with hot water and total leaf B positively correlated with doses of the nutrient applied to the trees. Levels of B in the soil and in the leaves did not vary with fertilizer sources. Fruit yield of trees grafted onto Rangpur lime and Swingle citrumelo was more responsive to B doses than those grafted onto Sunki mandarin. The maximum fruit yield of trees grafted onto Swingle was obtained with 3.2 kg ha-1 yr-1 of B, and leaf B level of 280 mg kg-1 that point out to a highest demand for B when this combination was compared with other rootstocks. Furthermore, fertilization with B did not affect the quality of fruits, but correlated with B and potassium （K） concentrations in the leaves. These results also support that the current recommendations for levels of B in leaves should be revisited.

Use of the SPAD-502 in Estimating Nitrogen Content in Leaves and Grape Yield in Grapevines in Soils with Different Texture

The SPAD reading may be used in estimating total nitrogen content (N) in leaves and even in estimating grape yield in grapevines. The objective of this study was to estimate total N content in leaves and grape yield using the SPAD-502 in grapevines submitted to nitrogen fertilization in soils with clayey and sandy texture. In 2008, two experiments were installed in the Southern region of Brazil. In experiment 1, Cabernet Sauvignon grapevines were planted in a soil with clayey texture and with application of 10, 20, 40 and 80 kg·N·ha-1·year-1. In experiment 2, Cabernet Sauvignon grapevines were planted in a soil with sandy texture and with the application of 0, 10, 15, 20, 40, 80 and 120 kg·N·ha-1·year-1. In the grapevines of the two experiments and during the period from 2008 to 2010, SPAD readings were made on leaves throughout the flowering period and at change in color of the berries using the portable chlorophyll meter Minolta-SPAD-502. The leaves were collected, dried, ground and submitted to analysis of the total N content. In addition, grape yield per hectare was evaluated. The SPAD-502 readings estimated the total N content in flowering and at change in color of the berries in the Cabernet Sauvignon grapevines grown on soils with clayey texture and sandy texture, especially in the first year of evaluation. However, the precision of the SPAD-502 readings is low, with there being no relationship between the SPAD-502 readings and grape yield.

Diagnosis of Boron Deficiency in Green Dwarf Coconut Palm

The diagnosis of boron deficiency in coconut palms has been hampered by lack of information about its distribution in the plant. Two experiments were conducted, one in a greenhouse to induce boron deficiency in dwarf green coconut palms, and other in the field, in which the plants received doses of boric acid, B(OH)3. The objective was to verify symptoms of boron deficiency and boron content variation in canopy, leaves and folioles (or leaflets). Boron deficient plants led leaves and folioles to become deformed. The deficient and sufficient contents of boron varied significantly in the canopy, but did not vary in leaves. The boron content increased significantly from bottom to the apex of the folioles in both treatments. To survey the level of boron in the coconut palm, the ideal is, using samples taken from the youngest leaf, to calculate the relation between the boron content in the apex of the foliole and the content in the center or in the folioles bottom, with minimum values 2.2 or 2.7, respectively.

Kinematic Analysis of Leaf Growth in Grasses:A Comment on Spatial and Temporal Quantitative Analysis of Cell Division and Elongation Rate in Growing Wheat Leaves under Saline Conditions

Hu and Schmidhalter （2008） conducted a study with wheat seedlings growing in saline and non-stressed （control） conditions with the aim of identifying and quantifying the cellular basis for the reduction in leaf growth. We applaud their goals as salinity is an important issue for plant ecology and food production; however, we have concerns about the methodology used and the subsequent conclusJons that are drawn.

Effect of Foliar Spray of Fe, GA3, Cultivars and Their Interactions on Growth of Olive （Olea europaea L.） Transplants cvs. Khithairy and Sorany

The study was conducted at the nursery of Malta station/Duhok. Kurdistan region-lraq, during the season 2011 to study the effect of GA3 and Fe on vegetative growth of two year old of two olive （Olea europaea L.） cultivars （Kithary and Sorany）, the transplant were sprayed with four levels （0, 250, 500 and 750 mg L^-1 GA3） and four levels of chelated iron （0, 25, 50 and 75 mg Fe L^-1）. Foliar application of GA3 at 500 mg Ll increased significantly stem diameter （mm）, leaf number, increasing GA3 level up 750 mg L^-1 significantly increase shoot length （cm） plantl, leaf area. However, 50 mg Fe L^-1 increased significantly leaf number, leaf area, chlorophyll content, and when treated with 75 mg Fe L^-1 significantly increase stem diameter, shoot length cm plant^-1, leaf fresh weight （g）, leaf dry weight （g）. While, Kithary cultivar significant dominated Sorany cultivar of the most studied characteristics. The interactions between GA3, Fe and cultivars significantly affected on the most of the characteristics studied, foliar sprays of Kithary cultivar with 750 mg Ll GA^-1 and 0 mg Fe Ll significantly increase chlorophyll content and leaf area, and Kithary cultivar when treated only by 75 mg Fe Ll increase significantly plant high （cm）, stem diameter （mm）, leaf dry weight （g） and leaf fresh weight when compared with the control.