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In this study, seedling populations of Camellia chekiangoleosa were analyzed to investigate their phenotypic variation, screen for superior individuals, and strengthen the conservation of genetic resources for breeding utilization. Variation, correlation, regression, and path analyses were performed on important economic traits. Principal component analysis as well as the subordinate function value and multidimensional coordinate synthetic evaluation methods were used to select the superior individuals. The results showed high phenotypic variation among the individual plants, with the coefficient of variation of 25 traits being 5.74%-57.16% and the diversity index being 1.934 6-2.095 9. The regression analysis revealed that the number of fruits, fresh seed weight per fruit, dry kernel weight per fruit, and kernel oil content were the key phenotypic traits affecting oil yield per plant. The path analysis identified the dry kernel weight per fruit as the main decision variable and the number of fruits as the main limiting variable. With principal component analysis, the 25 traits were transformed into 6 main principle components with a cumulative contribution rate of 86.557%. Nine superior individuals were screened out by using the above three methods. In conclusion, the high phenotypic variation among seedling populations of C. chekiangoleosa provides a material basis for the breeding of new high-yielding and high-quality varieties. [ABSTRACT FROM AUTHOR]

To improve our understanding of farmland surface process and agricultural water management in arid oasis area, we analyzed the characteristics of water and heat fluxes at different time scales, and the influence of arid advection and canopy conductance (Gc) on water and heat fluxes at different growth stages. In addition, we used path analysis to study the influence path of environmental factors on latent heat flux (LE) . In this paper, the water and heat fluxes were measured by eddy-covariance in 2017. The results were as follows: (1) LE showed multiple peaks, while the other fluxes were basically unimodal shapes at the daily scale. On the whole, the values of daily net radiation (Rn) were maximum, followed by LE, sensible heat flux (H) and soil heat flux (G) at each growth stage. The variation of diurnal G showed obvious lagged effect compared to that of Rn. (2) LE and H accounted for 86% and 14% (respectively) of daytime energy during the whole growing stages, indicating that LE was the main energy consumption item. The contribution of arid advection to daytime LE ranged from 5% to 59% with an average value of 28% at whole growing season. The influence of Gc on LE was stronger at the new shoot and leaf-fall stages than that in the middle growing season. (3) LE was mainly affected by Rn, followed by vapor pressure deficit (VPD) and air temperature (Ta), and the influence degrees of VPD and Ta on LE were similar. Furthermore, the path analysis showed that Rn directly affected LE; VPD and Ta mainly affected LE indirectly through Rn. As a whole, the water and heat fluxes in vineyards of arid desert oasis in Northwest China display significant diurnal and seasonal variations, and the influences of environmental factors on these exists great discrepancies in magnitude and path. [ABSTRACT FROM AUTHOR]

The photosynthetic physiological and ecological characteristics of plants are an important basis for the selection of plant species for restoration and reconstruction of degraded ecosystems. In order to study the photosynthetic physiological and ecological characteristics of different mangrove plants, from April to May in dry season and from July to September in rainy season of 2021, the LI-6400 photosynthetic measurement system was used to monitor the photosynthetic physiological parameters and main ecological factors of Kandelia obovata and Bruguiera sexangular in Dongzhaigang National Nature Reserve. The effects of major ecological factors on net photosynthetic rate were analyzed by using path analysis. The results were as follows:(1)The daily average net photosynthetic rate of Kandelia obovata in the dry season(8.43 μmol-2·s-1)was slightly lower than that in the rainy season(8.67 μmol-2·s-1), and the difference was not significant. In contrast, the rate of Bruguiera sexangular in the dry season(7.03 μmol-2·s-1)was significantly lower than that in the rainy season(9.41 μmol-2·s-1). The rate of Kandelia obovata was significantly higher than that of Bruguiera sexangular in dry season, while the rate of Kandelia obovata was significantly lower than that of Bruguiera sexangular in rainy season.(2)The daily average variations of transpiration rate, stomatal conductance and intercellular CO2 concentration of Kandelia obovata were smaller than those of Bruguiera sexangular and the water use efficiency was also lower than that of B. sexangular in dry and rainy seasons.(3)There was a phenomenon of “midday depression of photosynthesis” in both dry and rainy seasons of Kandelia obovata and Bruguiera sexangular. In dry season, the main reason for the phenomenon of Kandelia obovata might be due to non-stomatal limitation, while Bruguiera sexangular due to stomatal limitation. In rainy season, the phenomena of two mangrove plants were both mainly caused by stomatal limitation.(4)In the dry season, the main decision factor affecting the net photosynthetic rate of Kandelia obovata was photosynthetically active radiation, and the main limiting factor was relative humidity, while ecological factors played a limiting role on the net photosynthetic rate of Bruguiera sexangular of which saturated water vapor pressure difference was the main limiting factor. In the rainy season, the main decision factor was photosynthetically active radiation, and the main limiting factor was saturated water vapor pressure difference for both Kandelia obovata and Bruguiera sexangular. In summary, Kandelia obovata is more adaptable to habitat changes, and Bruguiera sexangular not only has better drought tolerance performance, but also more suitable for hot and rainy habitats, which will be the scientific reference for the selection of plant for restoration and reconstruction of degraded mangroves. [ABSTRACT FROM AUTHOR]

The high-quality development of grain industry is an inevitable requirement to improve the national food security level and meet the increasing needs of people for a better life. In order to meet the inherent requirements of consumption upgrading and supply-side structural reform of the grain industry in Guangdong-Hong Kong-Macao Greater Bay Area (GBA), and to improve the high-quality development and supply chain resilience of the grain industry in the GBA, it is theoretically and empirically analyzed from the perspective of the whole industrial chain of “production, purchase, storage, processing and sales”. and the endowment conditions such as soil, water, light and heat as well as the evolutionary changes of grain production in the GBA are sorted out. Then the current situation and existing problems of the grain industry in the GBA are empirically analyzed based on the situation of consumption, production, processing, storage and transportation. From 2010 to 2020, the reduction rate of cultivated land area in nine mainland cities was about 5%, of which the reduction rates of paddy field and dry land area were 3% and 8%, respectively. The cluster degree of grain production in the GBA was increasing continuously, and the total cultivation area of rice in Zhaoqing, Jiangmen, Huizhou and Guangzhou was increased from 91% in 2005 to 97% in 2020. By analyzing the main influencing factors and logical evolution mechanism of the grain industry in the GBA towards high-quality development, the difficulties and bottlenecks of “production, purchase, storage, processing and sales” were systematically deconstructed, and it was proposed to promote the high-quality development pattern of “great food, big industry, wide market and large circulation” of grain industry in the GBA with the approach of greater food; facilitate the division and deepening of “intra-industry” system - the key to the high-quality development of the grain industry in the GBA, implement the path of excellent production, storage, pricing, and processing of superior grain to build a brand value chain; adhere to the bottom line of ensuring a certain self-sufficiency rate in grain production in the GBA, vigorously develop high-quality flavortype rice on the basis of “superior grain and superior yield”, follow the strategy of differentiation and asymmetry with other major rice-producing provinces, innovatively propose the “selenium-rich rice project” in combination with the endowment conditions of the GBA, and carry out the plan of “double strength of grain production”; set a modernization pilot zone of the whole grain industry chain with Chinese characteristics, establish a grain reserve and emergency support center in the GBA, and create a long-term food security mechanism in the GBA based on the “dual circulation” strategy. [ABSTRACT FROM AUTHOR]

Grapes are one of the main economic crops in the arid area of Northwest China. Understanding its photosynthetic production process is very important for planting and cultivation. In order to analyze the physiological characteristics of grape photosynthesis and the main influencing factors affecting grape photosynthesis under natural conditions in the field, the daily variation of net photosynthetic rate of grape(variety: Seedless White) leaf and its daily variation of physiological and ecological factors in typical season of grape were measured from June to September in 2019. The path analysis method is used to analyze the direct and indirect effects of various factors on the net photosynthetic rate of grape leaf, and to determine its main influencing factors. In addition, the response of the net photosynthetic rate of grape leaf to various physiological and ecological factors was further analyzed in the whole day time-phased mode. The results were as follows: (1) The daily variation of net photosynthetic rate of grape leaf showed a single peak pattern, which first increased and then decreased; (2) The net photosynthetic rate of grape leaf was positively correlated with photosynthetic active radiation, vapor pressure deficit, air temperature, stomatal conductance and transpiration rate, and negatively correlated with relative humidity and intercellular CO2 concentration. Among them, the correlation coefficient with stomatal conductance and transpiration rate was the largest; (3) The main determinant that affected the variation of net photosynthetic rate of grape leaf was the transpiration rate in June, August and September, and the stomatal conductance in July; (4) The net photosynthetic rate of grape leaf in each month showed a “hysteretic loop” relationship with air temperature, photosynthetic active radiation, vapor pressure deficit, and a good linear relationship with transpiration rate and stomatal conductance(R²>0.85), and an exponential function relationship with intercellular CO2 concentration(R²=0.53). Studies have shown that grapes have a strong ability to adapt to the environment in the arid area of Northwest China. In cultivation, we can optimize management and increase yield by controlling transpiration rate and stomatal conductance, but the direct and indirect effects of other factors need to be considered. [ABSTRACT FROM AUTHOR]

This study was conducted in order to clarify the key factors affecting the density of regeneration sapling in mixed forests to facilitate the growth and regeneration of sapling in a spruce-fir coniferous and broad-leaved mixed forest. Taking a coniferous and broad-leaved mixed forest in northeast China as the research object, the site factors such as altitude, slope, and aspect of the sample plots were measured using the Voronoi diagram to determine the stand structure unit, calculate the stand structure index and perform statistical analysis of the number of trees for each tree species, and calculate the tree species diversity index. Pearson correlation and path analyses were then performed to explore the correlation between each influencing factor and the density of saplings in the mixed forest and ranked the contribution of each factor to the density of saplings. The results of the study showed that the average mingling degree of plots was 0.74,which belonged to intensity intermixing. The average uniform angle index of the plots was 0.43, and the forest divisions were evenly distributed. The condition of understory renewal saplings was not good; the distribution of base diameter showed small diameter for class saplings, and the overall situation was in a state of decline. Mingling degree, uniform angle index, Simpson index, Shannon index, and Pielou index had significant effects on the density of renewed saplings (P＜0.05), but the effects of other variables on the density of saplings were not obvious. The reason may be that the site factors in various places were not significantly different. The results of path analysis showed that the contributions of influencing factors to sapling density were ranked as follows: Simpson index＞Pielou index＞Shannon index＞mingling degree＞uniform angle index. Therefore, in order to improve the growth status of regenerating saplings in natural mixed forests, at this stage, the adjustment of the diversity of tree species should be the major measure. [ABSTRACT FROM AUTHOR]

Objective·To understand the status quo, influencing factors and action paths of health information seeking behavior in elderly patients with chronic diseases. Methods·From October 2020 to September 2021, five hundred and two elderly patients with chronic diseases in Ruijin Hospital, Shanghai Jiao Tong University School of Medicine were selected by objective sampling method. General Information Questionnaire, Health Literacy Management Scale (HeLMS), Chronic Disease Self-Efficacy Scale (CDSES), Health Information Seeking Behavior Scale were used. IBM SPSS 26.0 software and Mplus 8.3 software were used for statistics analysis. Results·The total average score of health information seeking behavior of elderly patients with chronic diseases was (3.30±0.40) points. The univariate analysis showed that different ages, residence, education, incomes, types of medical insurance, comprehensibility of health information, credibility of health information, self-efficacy, health literacy, and seeking health information for family members had statistically significant differences (all P<0.05). The path analysis results showed that comprehensibility of health information, self-efficacy, health literacy, education, credibility of health information, residence, type of medical insurance, income, and seeking health information for friends and families can directly affect health information seeking behavior, and the direct effects was 0.479, 0.225, 0.197, - 0.197, 0.154, 0.145, - 0.119, - 0.085, 0.070 (all P<0.05). Income, comprehensibility of health information, and health literacy can indirectly affect the health information seeking behavior of elderly patients with chronic diseases through the credibility of health information, and the indirect effects were -0.036, 0.033, 0.032 (all P< 0.05). Conclusions·The current status of health information seeking behavior among elderly patients with chronic diseases is poor. The most important influencing factor is the understandability of health information, and the main influencing factors are health literacy, self-efficacy, education, credibility of health information, residence, type of medical insurance, income, and seeking health information for friends and family. It is suggested that medical staff should understand the characteristics and influencing factors of health information seeking behavior, strengthen the assessment of health information seeking behavior, and implement timely intervention measures to improve health information seeking behavior of elderly patients with chronic diseases. [ABSTRACT FROM AUTHOR]

To understand the differences of soil enzyme activities and their relationships with soil nutrients in different topographies of the Maolan karst forest, the three different topographies of funnel, valley, and hillside were studied. The topographic differences of soil enzyme activities and the relationships of soil enzyme activity and soil nutrients were analyzed by one-way ANOVA and path analysis methods. The results showed that there were relatively large differences of soil nutrients among the different topographies. Specifically, soil nutrients were most abundant in funnels, followed by valleys and hillsides, respectively. Except for saccharase, the topographies had a significant effect on soil enzyme activity. The order of both catalase and saccharase activities in the different topographies was valley>funnel>hillside, that of alkaline phosphatase activity was valley>hillside>funnel, and that of urease activity was funnel>hillside>valley. Particularly, there was a weak correlation between the four soil enzyme activities and soil nutrients. The main influencing factors of catalase activity were total nitrogen and available nitrogen. The main influencing factors of alkaline phosphatase activity were available nitrogen and available potassium, the main influencing factor of urease activity was available potassium, and the main influencing factors of saccharase activity were total nitrogen and available potassium. The greater residual path coefficients of catalase, alkaline phosphatase, urease, and saccharase activities indicated that the four soil enzyme activities might be affected by other factors not considered in this work. The results of this research provide a theoretical basis for the maintenance of ecosystem structure and function and the maintenance mechanism of species diversity of the Maolan karst forest ecosystem. [ABSTRACT FROM AUTHOR]

Oil palm is the most important oil crop all over the world, its production is 30% of the world’s total vegetable oil, but there is still room for improving the yield. In order to verify relationship among fresh fruit bunch yield compo­nents, correlation between fresh fruit bunch yield and other traits were studied by using correlation, regression and path analysis. The results indicated that fresh fruit weight, number of bunch were the most closely related with fresh fruit bunch yield. Moreover, breeder should focused on average weight of fresh fruit bunch, number of fresh fruit bunch in each plant, fruit length, fruit width and oil content of mesocarp, and balance interaction among these characters was related with fresh fruit bunch yield in the high yield oil palm varieties breeding. Analysis of variance and correlation showed that the average shell thickness had the most coefficient of variation ( CV- 88.34%) , average fruit length had the least coefficient of variation (CV- 11.99%) , fresh fruit bunch yield had extremely significant positive correlation with average fresh fruit bunch weight, number of bunch produced, average fruit weight (r = 0.882 * * , 0.714 * * , 0.439 ** ) , and had significant positive correlation with average fruit length (0.334 * ). Multiple regression and path analysis showed that practical regression equation xx = -281.511+2 787x4+3.455.x5-2.672x6+0.41 l.x7+6.690x8 + 3.664x9 was established by comparing parameters related with multiple linear regression equation. Average fresh fruit bunch weight and number of bunch had maximum direct effects (0.670, 0.439) , other characters were relatively less, average fruit weight and average fruit length had maximum indirect effects (0.335, 0.322). The results provide information for the high yield varieties breeding. [ABSTRACT FROM AUTHOR]

The photosynthetic characteristics of five mangrove tree species in Techeng Island of Zhanjiang City were measured by Li-6400 photosynthetic measurement system to explore the factors on diurnal course of photosynthesis and evaluate their photosynthetic carbon fixation capacity. The results showed that daily variation of net photosynthetic rate in leaves of Kandelia candel and Rhizophora stylosa presented a single-peak curve, however, Avicennia marina, Bruguiera gymnorhiza and Aegiceras corniculatum presented a double-peak curve and an obvious “midday depression” phenomenon occurred, with the peak values at 10:00 am and 14:00 pm. Among them, midday-depression of photosynthesis in Avicennia marina and Bruguiera gymnorhiza was affected by stomatal limitation, however, Aegiceras corniculatum was affected by non-stomatal limitation. By path analysis, photosynthetic active radiation(PAR)was the decision factors and vapor pressure deficit(VPD)was the main limiting factors which affecting the characteristic of net photosynthetic rate(Pn)of Avicennia marina and Aegiceras corniculatum. In contrast to the situation of Avicennia marina and Aegiceras corniculatum, leaf temperature(Tl)was the main limiting factor and stomatal conductance(Gs)was the decision factor which affected Pn of Rhizophora stylosa and Kandelia candel. Gs was also the decision factors which affected Pn of Bruguiera gymnorhiza. The daily net carbon fixation amount was significant different among the five mangrove trees based on the leaf net photosynthesis rate, of which Kandelia candel was the highest(13.83 g·m-2·d-1), followed by Avicennia marina and Aegiceras corniculatum (9.48 and 8.24 g·m-2·d-1, respectively), the lowest was Bruguiera gymnorhiza and Rhizophora stylosa(6.72 and 6.30 g·m-2·d-1, respectively). The light compensation point(LCP)values of five mangrove trees ranged from 28.3 to 37.0 μmol·m-2·s-1 which showed the typical properties of sun plants. The light saturation point(LSP)values range between 169.3 and 1 189.3 μmol·m-2·s-1 of which Aegiceras corniculatum was the largest but Rhizophora stylosa is minimal. There were significant differences among the five mangrove tree plants of apparent quantum yield(AQY)(P<0.01), of which Avicennia marina was up to 0.064 mol·mol-1 while Bruguiera gymnorhiza was the lowest 0.005 mol·mol-1. The magnitude on grey correlation degree between light response parameters and daily net photosynthetic carbon fixation in leaves of mangrove tree species was the maximum net photosynthetic rate(Pmax), LSP-LCP, AQY, LSP and LCP. [ABSTRACT FROM AUTHOR]