Huangguan pear (Pyrus bretschneideri Rehd cv. Huangguan) is a pear cultivar that rapidly developed in China. However, rapid postharvest browning appearing in fruit peel and core during storage and shelf life pose a ch...Huangguan pear (Pyrus bretschneideri Rehd cv. Huangguan) is a pear cultivar that rapidly developed in China. However, rapid postharvest browning appearing in fruit peel and core during storage and shelf life pose a challenge for their marketing. The potential for low temperature conditioning (LTC) treatment to inhibit peel browning and improve quality of Huangguan pears in storage and shelf life was investigated. Pears were treated at 8℃ - 9℃ for 1, 3, 6 and 9 d, respectively, physiological indexes, including peel and core browning, core breakdown, malondialdehyde (MDA) content and ethanol content were determined and quality in storage period and shelf life was evaluated in this paper. LTC treatment alleviated peel browning and core browning either in storage or shelf life remarkably;it also delayed the decline of firmness, total soluble solids and titratable acidity in storage to some extent, inhibited ethanol and MDA content both in storage and shelf life effectively and maintained juiciness and crispness of pear fruit in shelf life. These results showed that LTC can serve as an important tool for the regulation of Huangguan pears external and internal quality in storage and shelf life with economic benefits and LTC treatment for 6 d was the optimum condition in the present study.展开更多
Crop performance is determined by the combined effects of the genotype of the crop and the environmental conditions of the production system. This study was undertaken to develop a dynamic model for simulating environ...Crop performance is determined by the combined effects of the genotype of the crop and the environmental conditions of the production system. This study was undertaken to develop a dynamic model for simulating environmental （temperature and solar radiation） and N supply effects on fiber fineness, maturity and micronaire. Three different experiments involving genotypes, sowing dates, and N fertilization rates were conducted to support model development and model evaluation. The growth and development duration of fiber fineness, maturity, and micronaire were scaled by using physiological development time of secondary wall synthesis （PDT SWSP ）, which was determined based on the constant ratio of SWSP/ BMP. PTP （product of relative thermal effectiveness （RTE） and photosynthetically active radiation （PAR）, MJ m-2） and subtending leaf N content per unit area （N A , g m-2） and critical subtending leaf N content per unit area （CN A , g m-2） of cotton boll were calculated or simulated to evaluate effects of temperature and radiation, and N supply. Besides, the interactions among temperature, radiation and N supply were also explained by piecewise function. The overall performance of the model was calibrated and validated with independent data sets from three field experiments with two sowing dates, three or five flowering dates and three or four N fertilization rates for three subsequent years （2005, 2007, and 2009） at three ecological locations. The average RMSE and RE for fiber fineness, maturity, and micronaire predictions were 372 m g-1 and 5.0%, 0.11 m g-1 and 11.4%, 0.3 m g-1 and 12.3%, respectively, indicating a good fit between the simulated and observed data. It appears that the model can give a reliable prediction for fiber fineness, maturity and micronaire formation under various growing conditions.展开更多
[目的]探讨贮藏温度对果实品质及生理的影响。[方法]以宁夏中部干旱带‘玉金香’甜瓜(Cucum is meloL.var Yujinxiang)为试材,研究了不同贮藏温度(5、10和20℃)条件下其成熟期果实主要品质、生理代谢和采后病害发生的情况。[结果]采后...[目的]探讨贮藏温度对果实品质及生理的影响。[方法]以宁夏中部干旱带‘玉金香’甜瓜(Cucum is meloL.var Yujinxiang)为试材,研究了不同贮藏温度(5、10和20℃)条件下其成熟期果实主要品质、生理代谢和采后病害发生的情况。[结果]采后不同贮藏温度条件下果实硬度均呈逐步下降趋势,5℃贮藏硬度值下降最慢,说明低温有利于保持果实硬度。可溶性固形物(TSS)含量呈逐步下降趋势,低温贮藏可延缓TSS含量下降的趋势。贮藏初期,果实呼吸强度均呈下降趋势,温度越低呼吸强度下降越快,采后4 d呼吸发生跃变,在8 d时达到高峰,贮藏温度越高呼吸跃变峰值越大。低温贮藏可部分抑制呼吸强度的增加。乙烯释放量的变化与呼吸强度的变化趋势相似。采后可溶性果胶含量呈逐步增加趋势,贮藏温度越高增加越快。采后贮藏期果实病害严重,7 d后普遍发病,20℃病害最严重,10℃病害最轻,5℃贮藏后期果实有冷害现象,反而加重了病害。10℃是玉金香采后的最佳贮藏温度。[结论]为甜瓜的保鲜工作提供了理论依据。展开更多
文摘Huangguan pear (Pyrus bretschneideri Rehd cv. Huangguan) is a pear cultivar that rapidly developed in China. However, rapid postharvest browning appearing in fruit peel and core during storage and shelf life pose a challenge for their marketing. The potential for low temperature conditioning (LTC) treatment to inhibit peel browning and improve quality of Huangguan pears in storage and shelf life was investigated. Pears were treated at 8℃ - 9℃ for 1, 3, 6 and 9 d, respectively, physiological indexes, including peel and core browning, core breakdown, malondialdehyde (MDA) content and ethanol content were determined and quality in storage period and shelf life was evaluated in this paper. LTC treatment alleviated peel browning and core browning either in storage or shelf life remarkably;it also delayed the decline of firmness, total soluble solids and titratable acidity in storage to some extent, inhibited ethanol and MDA content both in storage and shelf life effectively and maintained juiciness and crispness of pear fruit in shelf life. These results showed that LTC can serve as an important tool for the regulation of Huangguan pears external and internal quality in storage and shelf life with economic benefits and LTC treatment for 6 d was the optimum condition in the present study.
基金funded by the National Natural Science Foundation of China (30771277 and 30771279)
文摘Crop performance is determined by the combined effects of the genotype of the crop and the environmental conditions of the production system. This study was undertaken to develop a dynamic model for simulating environmental （temperature and solar radiation） and N supply effects on fiber fineness, maturity and micronaire. Three different experiments involving genotypes, sowing dates, and N fertilization rates were conducted to support model development and model evaluation. The growth and development duration of fiber fineness, maturity, and micronaire were scaled by using physiological development time of secondary wall synthesis （PDT SWSP ）, which was determined based on the constant ratio of SWSP/ BMP. PTP （product of relative thermal effectiveness （RTE） and photosynthetically active radiation （PAR）, MJ m-2） and subtending leaf N content per unit area （N A , g m-2） and critical subtending leaf N content per unit area （CN A , g m-2） of cotton boll were calculated or simulated to evaluate effects of temperature and radiation, and N supply. Besides, the interactions among temperature, radiation and N supply were also explained by piecewise function. The overall performance of the model was calibrated and validated with independent data sets from three field experiments with two sowing dates, three or five flowering dates and three or four N fertilization rates for three subsequent years （2005, 2007, and 2009） at three ecological locations. The average RMSE and RE for fiber fineness, maturity, and micronaire predictions were 372 m g-1 and 5.0%, 0.11 m g-1 and 11.4%, 0.3 m g-1 and 12.3%, respectively, indicating a good fit between the simulated and observed data. It appears that the model can give a reliable prediction for fiber fineness, maturity and micronaire formation under various growing conditions.
