Physiological Changes during the Process of Pericarp Browning in the Postharvest Litchi

[Objective] Pericarp browning in the postharvest litchi significantly reduced its commercial value and limited the expanding of litchi markets. Physiological changes during the process of pericarp browning were determined in order to identify the underlying mechanisms. [Method] Matured Feizixiao fruits were stored at 25 ℃ and 70%±5% relative humidity. The physiological changes happened in pericarp during storage were tested at an 8-hour interval. [Result] The fruit of Feizixiao (Litchi chinensis Sonn. cv Feizixiao) turned completely brown within 72 h after being harvested under the experimental conditions. Sharp increase of the browning index occurred from 48 to 64 hours after harvest (HAH). With the browning of pericarp,water content of the whole fruit and pericarp decreased continuingly. In contrast,there were no significant changes in the water content of pulp during the same period. MDA content,pH value and relative leakage rate of pericarp were increased during storage. Most of pigment contents including anthocyanin,flavonoid,phenols,chlorophyll a and total chlorophyll decreased. POD activity was initially increased in 32 HAH and then decreased afterwards. PPO activity was decreased continuously,while the activities of catalase and superoxide dismutase exhibited the pattern of 'increasing-decreasing-increasing' as the storage time progressed. Correlation,stepwise regression and path analyses showed that water loss of pericarp was the major factor of pericarp browning. Principal and cluster analyses showed that there were two stages of pericarp browning during the course of litchi storage. [Conclusion] Water status of pericarp was the most important factor affecting pericarp browning. The pericarp browning happened by stages,which was mainly determined by the water loss of pericarp.

Identification of coastal water quality by multivariate statistical techniques in two typical bays of northern Zhejiang Province,East China Sea

The Hangzhou Bay（HZB） and Xiangshan Bay（XSB）, in northern Zhejiang Province and connect to the East China Sea（ECS） were considerably affected by the consequence of water quality degradation. In this study, we analyzed physical and biogeochemical properties of water quality via multivariate statistical techniques. Hierarchical cluster analysis（HCA） grouped HZB and XSB into two subareas of different pollution sources based on similar physical and biogeochemical properties. Principal component analysis（PCA） identified three latent pollution sources in HZB and XSB respectively and emphasized the importance of terrestrial inputs, coastal industries as well as natural processes in determining the water quality of the two bays. Therefore, proper measurement for the protection of aquatic ecoenvironment in HZB and XSB were of great urgency.

Evaluation of Sorghum (Sorghum bicolor) Landraces for Drought Tolerance Using Morphological and Yield Characters under Rainfed Conditions of Sub Region Hagaz, Eritrea

Sorghum is an important food crop in Eritrea where it is widely grown in the mid and low lands,of semi-arid regions.Eritrea being the center of ori­gin of sorghum,a large variability exist in its landraces being grown by the farmers since generations.In order to improve the productivity of sorghum under moisture stress conditions,it is imperative to evaluate these landraces for drought tolerant characteristics and their use for further crop improve­ment programmes.Therefore,a field study was conducted in a randomized complete block design with three replications to estimate the extent of genetic variability of 20 sorghum genotypes for moisture stress tolerance using various morphological,phenological,yield and yield related parame­ters under rainfed conditions at Hagaz Research Station.Significant differ­ence was observed for almost all the characters in the individual analysis of variance suggesting that these sorghum accessions were highly variable.Accessions EG 537,EG 1257,EG 849,EG 791,EG 783 and EG 813 showed promising results for post flowering drought tolerance,grain yield and stay green traits.Higher PCV and GCV were also obtained in parame­ters like plant height,leaf area,biomass,peduncle exertion,panicle length,and grain yield and panicle weight.The genotypes also exhibited varying degrees of heritability estimates.Characters such as plant height,panicle length,days to flowering and maturity showed higher heritability.Cluster analysis revealed that sorghum landraces were grouped on the basis of their morphological traits and geographical sites.77.3%of the total variation of sorghum landraces was contributed by the first four principal components analysis having Eigen value>1.Overall,the current study confirmed that EG 537,EG 849,EG 1257,EG 791,and EG 813 are drought tolerant sor­ghum landraces during post flowering stage.