Using cotton cultivar that undergoes premature senescence in the late stage of growth, we studied the effects of removing two basal fruiting branches of two cotton varieties, namely, Quanyin-2 and Jiza-999, on the leaf area index, the SPAD value of leaf subtending cotton boll, and the development of cotton fiber in the late stage of cotton growth. We focused on the differences in cotton cellulose accumulation and fiber-related enzyme activities after removal of the basal fruiting branches and the development of cotton fiber during premature senescence. The results showed that removing the basal fruiting branches can maintain the green leaf area of the cotton canopy and the SPAD value of the subtending leaf during the late stage of reproductive growth. The period of rapid accumulation of fiber cellulose lasted longer in plants from which the basal fruiting branches had been removed, and the beginning and end of the rapid accumulation period was later than in the control group with premature senescence. The activities of cellulose synthesis-related enzymes (sucrose phosphate synthase, sucrose synthase, beta-1,3-glucanase, and invertase) were higher in plants in which the basal fruiting branches had been removed than in the control group after 10 days post-anthesis. Removing the basal fruiting branches can optimize the accumulation of cellulose in cotton boll during the late growth stage and mitigate the effects of premature senescence on cellulose synthesis. We found that the peak values for cotton fiber development-related enzyme activities in the control group occurred earlier, which tended to bring cotton fiber development forward and negatively impacted fiber yield.
Influence of water on the dielectric properties of jujube, yellow-locust, and vitex honey was investigated by dielectric spectroscopy in broadband from 40 Hz-40 GHz. At lower frequencies, two relaxations which were from interface polarization and dipole orientation polarization of macromolecules in honey were observed. Other relaxations contributed by free and bound water were observed at microwave frequencies. The analysis of the observed relaxations revealed that the honey/water interface and bound water molecules that interact with the macromolecules in honey are responsible for the changed dielectric properties of honey solutions. Besides, the linear correlations between the permittivity (around 2.45 GHz) and water content of honey solutions were developed, which indicates that water content in honey solutions can be measured by dielectric spectroscopy. In addition, we also compared the dielectric properties of different pure honey types and found that the pure yellow-locust honey, which contains the maximum water content, has the highest permittivity. This suggests that different honey types with different water content can be roughly identified by dielectric spectroscopy. This study shows that the water content influences the dielectric properties of honey and dielectric spectroscopy is feasible for detecting honey adulteration with water.
The study was conducted to assess the effect of different wax coating materials and Modified Atmosphere Packaging (MAP) on storage life and quality of 'Kaghzi lime' (Citrus aurantifolia Swing.) fruits. The fruits were harvested at light yellow skin color stage and treated with different wax coating materials: T1= Citrus Wax (wood resins18%, Imazalil 0.3%, Thiabendazloe 0.5%), T2= PHRC SCM Wax [9% total solids (castor and shellac based wax)]; T3= Modified Atmosphere Packaging (MAP), and T0= The fruit without any treatment were used as control. The fruits were stored at 10 degrees C for 45 days and relative humidity was maintained at 90%. Physiochemical, sensory, organoleptic, and quality parameters were measured after 30 and 45 days of harvesting. The coating treatments significantly (P <= 0.05) reduced physiological weight loss, increased shelf life and maintained the quality of fruits. Among all treatments, Citrus Wax proved best because it maintained relatively higher levels of acidity, flavor, vitamin C content and fruit firmness; prevented disease attack; and improved juice recovery of lime fruits compared with control. Thus this treatment can be used to enhance the shelf life and maintain quality of the lime fruits.
Low temperature is a limiting factor of seed germination and plant growth. In this study, two independent experiments were conducted to investigate the effects of low temperature on germination, early seedling growth and antioxidant systems in two provenances of Elymus nutans Griseb. (Damxung, DX and Gannan, GN). The seeds and early seedlings of DX were more tolerant to low temperture than those of GN. Low temperature (5 degrees C) negatively affected seed Germination Percentage (GP), Germination Energy (GE) and the First Germination Time (FGT) in both provenances of E. nutans. Low temperature also increased Mortality Percentage (MP) when compared with control plants grown at 25 degrees C. Low temperature treatments significantly reduced length and fresh/dry weight of shoots and roots in the two accessions after 29 days of exposure to 5 degrees C. In the second experiment, after 5 days of low temperature treatment, DX exhibited significantly higher Chlorophyll (Chl) and Carotenoid (Car) content as well as increased activities of Peroxidase (POD), SuperOxide Dismutase (SOD), Catalase (CAT). In contrast we observed lower Electrolyte Leakage (EL) and reduction of the amounts of MalonDiAldehyde (MDA), Hydrogen peroxide (H2O2) and superoxide radical (O-2(center dot-)). We conclude that GN is more susceptible to low temperature than DX due to more severe oxidative damage resulting from Reactive Oxygen Species (ROS) and lower antioxidant enzyme activities.