Ethylene-inhibiting compound 1-MCP delays leaf senescence in cotton plants under abiotic stress conditions

Cotton （Gossypium hirsutum L.） plants produce more ethylene when subjected to abiotic stresses, such as high temperatures and drought, which result in premature leaf senescence, reduced photosynthetic efficiency, and thus decreased yield. This study was conducted to test the hypothesis that the ethylene-inhibiting compound 1-methylcyclopropene （I-MCP） treatment of cotton plants can delay leaf senescence under high temperature, drought, and the aging process in controlled environ- mental conditions. Potted cotton plants were exposed to 1-MCP treatment at the early square stage of development. The protective effect of 1-MCP against membrane damage was found on older compared to younger leaves, indicating 1-MCP could lower the stress level caused by aging. Application of 1-MCP resulted in reduction of lipid peroxidation, membrane leakage, soluble sugar content, and increased chlorophyll content, in contrast to the untreated plants under heat stress, suggesting that 1-MCP treatment of cotton plants may also have the potential to reduce the effect of heat stress in terms of delayed senescence. Application of 1-MCP caused reductions of lipid peroxidation, membrane leakage, and soluble sugar content, together with increases in water use efficiency （WUE）, water potential, chlorophyll content, and fluorescence quantum efficiency, compared to the untreated plants under drought, suggesting that 1-MCP treatment of cotton plants may also have the ability to reduce the level of stress under drought conditions. In conclusion, 1-MCP treatment of cotton should have the potential to delay senescence under heat and drought stress, and the aging process. Additionally, 1-MCP is more effective under stress than under non-stress conditions.

Changes in Nutritive Materials in Off-season Mango in Flower Bud Differentiation Stage

Under off-season production mode, change laws of nutritive materials in leaves of fruiting mother branches of mango in flowering process induced by dif- ferent agents were investigated. The results showed that the flowering time of manga trees in the potassium nitrate treatment was earlier than the ethephon treatment by 7 d, and changes trends of materials in leaves of the potassium nitrate and ethephon treatments were substantially the same. The nutritive materials in leaves showed trends of increasing at first and decreasing then. In early flower bud differentiation stage, soluble sugar and starch in leaves increased rapidly, and content of soluble protein also increased rapidly and showed its their peak values, thereby providing energy substances and structural substances demanded by flower bud formation. With flower bud differentiation going on, soluble sugar, starch and soluble protein decreased gradually. It was indicated that the accumulation of soluble sugar, starch and soluble protein is beneficial to flower bud differentiation.

The Effect of Magnesium on Accumulations of Primary Metabolites and Yield of Blumea balsamifera

[Objectives]This study was conducted to investigate the effects of magnesium on the yield of Blumea balsamifera(L.)DC.and the accumulation of primary metabolites that affect yield of the medicinal material.[Methods]The annual seedlings of B.balsamifera were selected as experimental materials.The treatment concentrations of magnesium(Mg)were set as 0,1.5,15 and 150 mg/ml supplied by MgSO4·7H2O.The yield of the medicinal material was measured dynamically.And the content of total sugar was determined by 3,5-dinitrosalicylic acid colorimetry;the content of crude protein was determined by the Kjeldahl method;the ash content was determined by the high-temperature burning method;the crude fat content was determined with a crude fat instrument;and the crude fiber content was determined by the acid-base washing and weighing method.[Results]Mg significantly increased the yield of B.balsamifera medicinal material,especially 15 mg/ml Mg.It was found that in September,October and November,1.5 mg/ml and 15 mg/ml Mg significantly increased the contents of primary metabolites including total sugar,ash,crude protein,crude fat and crude fiber,and 150 mg/ml of Mg increased the accumulation of total sugar,ash,crude protein and crude fiber to different degrees,but had certain inhibitory effect on the accumulation of crude fat.In December,the application of Mg inhibited the accumulation of total sugar,ash and crude protein to different degrees,but significantly promoted the accumulation of crude fat and fiber.[Conclusions]This study provides a theoretical basis for clarifying the effects of different concentrations of magnesium on plant growth.

Development of a Compound Photorespiration Inhibitor and Its Application on Sweet Cherry

[Objectives]This study was conducted to investigate the effects of compound photorespiration inhibitors on related indexes of sweet cherry.[Methods]With the main sweet cherry variety‘Meizao’as a test material,relevant research work was carried out.[Results]Several compound photorespiration inhibitors had a better promotion effect on the photosynthetic capacity,yield and quality of sweet cherry variety‘Meizao’,and especially,the combination of 300 mg/L sodium bicarbonate,300 mg/L sodium bisulfite,300 mg/L 2,3-epoxypropionic acid and 1.5%tween-80 had the best effect.[Conclusions]The combined use of the three photorespiration inhibitors is better than the single use,and produces a good synergistic effect.

Quality of Melon 'UFERSA-05 var.ACIDULUS and Pele de Sapo“Mabel”Minimally Processed,Kept in Different Packages

This study aimed at evaluating the quality of melon Pele de Sapo “Mabel” and Yellow melon “UFERSA-05” minimally processed preserved in different packages. The fruits were harvested at Mossoró-RN and transported to Serra Talhada-PE. In the first study, melon fruit Piel de Sapo “Mabel” was selected, washed, weighed, cooled, peeled, cut into cube shape, sanitized in chlorine solution, drained, packaged in rigid polypropylene tray, sealed with polypropylene film or polypropylene rigid cap and kept for 8 days at 8℃. In the second study, fruits of yellow melon “UFERSA-05” and Pele de Sapo “Mabel” were minimally processed and kept in rigid polypropylene tray, sealed with polypropylene film and stored for 8 days at 8℃. There was no significant interaction between packaging (sealed with film and polypropylene cover) and period of conservation, for pH, total titratable acidity (TTA), total soluble solids (TSS) and Loss of fresh mass (LFM) for Melon “Mabel”. While there was significant interaction between types of melon (“UFERSA-05” and “Mabel”) and storage period (0, 2, 4, 6, and 8 days) for pH, TTA and TSS. In sensory evaluation were noticeable changes in appearance, flavor, aroma and flesh firmness, characterized by translucency, alcoholic aroma and softening in “Mabel” melon kept in tray with lid. Melon “UFERSA-05” showed lower pH, total soluble solids, total soluble sugars, PME activity, lack of translucency high flesh firmness compared to “Mabel” melon during storage. The high levels of sugars in melon “Mabel” may be related to the incidence of translucency, which was not observed in “UFERSA-05” melon, with a strong potential to minimal processing.

Analysis of moisture and total sugar content of Huizao based on surface images

Moisture and total sugar content are two important internal qualities of Huizao.In order to explore their correlation with external qualities,a novel method of moisture and total sugar content analysis was proposed based on surface images.Firstly,five geometric features and seven texture features of Huizao were obtained to be the external quality indexes by digital image processing technology.Secondly,the wrinkle degree as an important index was extracted by marked watershed segmentation algorithm.According to the external quality the Huizao samples were grouped,and the moisture and total sugar content were determined through physical and chemical methods.Lastly,the moisture and total sugar content and twelve external indexes were all processed by step discriminatory analysis.Meanwhile,the regression models of moisture content with short diameter,contrast,and wrinkle degree and total sugar with wrinkle degree were established.The coefficients of the model were 0.9992 and 0.9978 respectively,and all the significance was less than 0.01,which show that the regression equation and regression coefficient effect are highly significant.The results indicate that the moisture and total sugar content of Huizao are greatly correlated with the wrinkle degree.The moisture and total sugar content are the highest when the wrinkle degree is at 2 to 3 grade,and they decrease gradually with the wrinkle degree increasing.Moisture content shows positive correlation with the size of Huizao.The results of model analysis agree well with the experimental results,which can provide valuable reference for improving Huizao grade diversity.

Accumulation of cadmium and its effects on growth, development and hemolymph biochemical compositions in Boettcherisca peregrina larvae （Diptera： Sarcophagidae）

Newly emerged larvae of the fleshfly, Boettcherisca peregrina were exposed to two different CdCl2 concentrations of 100μg/g and 400 mg/g diet fresh weight （DFW）. They were administered in the diets until the end of larval stage. Cd-exposed larvae accumulated significant amounts of Cd and this accumulation increased with the exposure dose and time. The body weights were lightened and lengths of larvae were shortened considerably after Cd exposure, especially at the higher Cd concentration. The total larval duration was also extremely affected due to Cd exposure. The average duration was prolonged significantly by 14 h at the lower Cd concentration, while it was increased by 33.7 h over controls at the higher Cd concentration. A significant decrease in contents of either soluble proteins, total lipids or caloric values in the hemolymph occurred due to Cd exposure throughout the entire tested period but after 120 h of Cd exposure. In contrast, when exposed to Cd with its higher concentration, total sugar contents in the hemolymph were increased strikingly over the whole tested time, except after 96 h of Cd exposure, while they were not apparently altered except after 24 h of Cd exposure at the lower concentration. Thus, it is suggested that Cd exposure shows significant adverse impact on the growth and development, as well as metabolism, in larvae of this fleshfly, depending on its exposure time and dose.

Physiological Responses of Zea mays Seedlings to Interactions Between Cadmium and Salinity

The effects of 0, 2.5, 5.0, and 10.0 pmol/L Cd^2＋（Cd（NO3）2.4H2O） and 0, 10, 25, 50, and 100 mmol/L NaCl on growth, photosynthesis and the content of some ions in maize （Zea mays L.） were investigated in the present study. With Increasing concentrations of Cd^2＋ or NaCI alone in Hoagland nutrient solution, the chlorophylls and starch content decreased. Combination treatment with salinity and cadmium increased the negative effects observed following the two stresses alone. Plants exhibiting growth retardation in response to one mild stress factor （25-50 mmol/L NaCl） became more tolerant to the other stress factor （Cd）. The exposure of plants to cadmium caused a partial reversal of the effects of salinity. Root and shoot growth, ion accumulation and levels of photosynthetic pigments were improved at moderate concentrations of the two stress factors Imposed jointly.