Research Progress of Selenium-enriched Agricultural Crops and Horticultural Crops in China

Selenium（Se） is one of the essential trace elements required by humans and animals. It will cause diseases for humans and animals when Se is excessive or lack in the environment.The research status of selenium-enriched agricultural crops and selenium-enriched horticultural crops, functional mechanism and application status of selenium, and the latest progress in the study of selenium enrichment were summarized in this paper.

Genome Editing as A Versatile Tool to Improve Horticultural Crop Qualities

The quality traits of horticultural crops,including the accumulation of nutrients and flavor substances,morphology,and texture,affect the palatability and nutritional value.For many years,efforts have been made to improve the quality of horticultural crops.The recent establishment of gene editing technology,with its potential applications in horticultural crops,provides a strategy for achieving this goal in a rapid and efficient manner.Here,we summarize research efforts aimed at improving horticultural crop quality through genome editing.We describe specific genome editing systems that have been used and traits that have been targeted in these efforts.Additionally,we discuss limiting factors and future perspectives of genome editing technology in improving horticultural crop qualities in both research and plant breeding.In summary,genome editing technology is emerging as a powerful tool for efficiently and rapidly improving horticultural crop quality,and we believe that the cautious application of genome editing in horticultural crops will generate new germplasms with improved quality in the near future.

Light regulation of horticultural crop nutrient uptake and utilization

Plants demonstrate dynamic changes in molecular structures under fluctuating light conditions.Accumulating evidence suggests that light plays a vital role in plant growth and morphogenesis.In particular,light has a role in the absorption and utilization of nutrients in plants.Despite significant progress in understanding the mechanism of nutrient acquisition and assimilation,how light affects and regulates ion uptake remains a question.Studies in model plants,Arabidopsis thaliana,suggest that light affects the nutrient utilization in roots through a complex regulatory network;nonetheless,the molecular mechanisms underlying the various effects of light on these processes in crop plants remain fragmentary.In this review,we discuss the light effects(light quality,light intensity,and photoperiod)on nutrient uptake and utilization in horticultural crops for optimizing crop productivity and increasing fertilizer use efficiency.

Nanotechnology-Based Advancements in Postharvest Management of Horticultural Crops

Horticulture is a branch of Agricultural science where it is defined as the science and art of cultivating and handling fruits,vegetables,ornamental plants and several plants having unique medicinal and aromatic values.Horticultural crops provide farmers with high income and have good export quality,but they have a concern about postharvest losses.Hence,increasing productivity and decreasing post-harvest losses by using scientific studies and techniques like biotechnology and nanotechnology could be the simplest possible solution to the above-mentioned problems.Using nanotechnology which is having the characteristics of nanoparticles is proven to be very useful in science and technological applications.Nanotechnology-based formulations increase the product quality and the shelf life of horticultural products and provide multiple ways of inhibiting the growth and development of microorganisms.It is precisely a new edible packaging coverage(film)that controls the exchange of gases and prevents damage from harmful rays such as ultraviolet radiation to a greater extent.Increasing strength by using nano biosensors for labeling products is considered a fundamental process to automated control of storage products.Postharvest rotting of vegetables is recognized to be an oxidative reaction and microbial deterioration as well.This review will address all such nanotechnology-based advancements for minimizing post-harvest losses of horticultural crops and enhancing the socio-economical progress of growers in particular.

Integrated Control of Diseases and Pests of Horticultural Crops

In view of the occurrence and aggravation of diseases and pests of horticultural crops,the management process should follow the basic policy of"prevention first,comprehensive control".Starting from the ecological system,agricultural,biological,physical and chemical means should be comprehensively applied to control diseases and pests below the economic injury level.

Carotenoid Pigment Accumulation in Horticultural Plants

Carotenoids are a group of widely distributed natural pigments.They give many horticultural plants the bright red,orange,and yellow colors,as well as the aroma and flavor.Carotenoids enhance the health value and represent an essential quality trait of horticultural products.Significant efforts have been made to correlate specific carotenoid production with pathway gene expression.Some transcription factors that directly regulate transcription of the pathway genes have been identified.Horticultural crops have evolved with complicated and multifaceted regulatory mechanisms to generate the enormous diversity in carotenoid content and composition.However,the diverse and complex control of carotenoid accumulation is still not well understood.In this review,we depict carotenoid accumulation pathways and highlight the recent progress in the regulatory control of carotenoid accumulation in horticultural plants.Because of the critical roles of chromoplasts for carotenoid hyperproduction,we evaluate chromoplast ultrastructures and carotenoid sequestrations.A perspective on carotenoid research in horticultural crops is provided.

Jordanian Horticultural Export Competitiveness from Water Perspective

The main objective of this paper is to analyze the relationships between the productive process and the commercial trade with water resources used by them. For that the goal is to find out, by means of the estimation of water embodied in the exported crops which have the highest export competitiveness and lower water consumption. The finding contradicts not only the comparative advantages theory but also the resources sustainability logic. This conclusion is derived from the great exports of water via tomatoes and low profitable vegetables from producers＇ perspective but not economical from social perspectives as shown in domestic resource coefficient. The diversion between financial and economic profitability is due to heavily irrigation water subsidy. The results confirm that Jordan utilizes large amounts of water in its exports, and in turn, it does not export goods with low water requirements. The potential saving would be very significant and agricultural sector need to modify the use of water to a great extent in order to reach significant water savings and an environmental sustainability. Jordan has to implement policies that reduced, or even abandoned, the export and the production of water-intensive crops. Therefore, they have to be replaced with either imports or crops that optimize the water resources.

Application of Trichoderma harzianum (T22) and Trichoderma atroviride (P1) as plant growth promoters, and their compatibility with copper oxychloride

Trichoderma strains are used in agriculture because they provide to the plants the following benefits: i) are rhizosphere competence and establish stable rhizosphere microbial communities; ii) control plant disease caused by pathogenic and competitive microflora, by using a variety of mechanisms; iii) improve vegetative growth, root development and yield; iv) make nutrients more available to the plant. In this work we have investigated the ability of T. harzianum T22 and T. atroviride P1 to improve plant growth of locally important horticultural crops: lettuce, tomatoes and peppers and to prevent disease in the greenhouse and field. The effect of the Trichoderma treatment was evaluated by determining the weight of fresh and dry roots and above ground plant biomass, measuring plants height, counting the number of emerged leaves (lettuce, tomatoes and peppers) and quantifying production (tomatoes and peppers). No disease symptoms were found during production, although Fusarium sp. strains pathogenic to tomato were detected in the soil. Compounds containing copper oxychloride are frequently used for fungal disease control in agriculture. In order to investigate the compatibility of T. harzianum T22 and T. atroviride P1 with copper oxychloride applications, the effect on mycelia growth was monitored in both liquid and solid medium. In general, the tests indicated a high level of tolerance of the Trichoderma strains to concentrations of copper oxychloride varying from 0.1 to 5 mmol/L.

Estimation of the Economic Value of Irrigation Water in Jordan

Insight into the different values of water is essential to support rational decision making about policies, management and investments in the water sector. The main objective of this paper is to estimate an economic value of irrigation water in Jordan by choosing appropriate methodology fit with available data. The Residual Imputation Method （RIM） is used to determine the average economic value of irrigation water used in agriculture across crops. The results showed that the weighted average of water value used in field crops is JD 0.44 m＂3 and JD 1.23 m3 for vegetable crops and JD 0.23 m3 for fruit trees. The overall weighted average water value in irrigation is estimated with JD 0.51 m＂3. With regard to individual crops, cucumbers had the highest water values with about JD 6.05 m3, followed by string beans with JD 2.64 m3, and sweet pepper with JD 2.54 m3. The lowest returns per m3 were provided by squash, radish and hot pepper. For fruit tress banana has the highest water value JD 0.79 m3 and olive tress has the lowest with only JD 0.069 m3. The current practice of some banana producers is economically rational by installing Reverse Osmosis unit to irrigate banana, since water value is twice the desalination costs of one cubic meter. The estimated values represent the maximum price that farmers might be willing to pay for water under the current market conditions. Water subsidy distorts farmers＇ perception of water as a scarce and thus valuable resource. Low water prices are thus likely to engender excessive use. It is necessary to allow water prices to recover the real cost of water supply and to ensure financial sustainability of water utilities.

Characterization of Farming Systems Using Land as a Driver of Production and Sustainability in the Vhembe District, Limpopo, South Africa

South African agricultural farming systems are characterised by a duality in which there exists large-scale commercial farmers and small-scale farmers. Large-scale commercial farmers, historically identified as capital intensive and characterized by the size of the landholdings, are considered as the main drivers of national food security. Small-scale farmers on the other hand are viewed as important drivers of food security at the household level. These two main farming systems can be found within the Vhembe district municipality of the Limpopo Province and are characterised differently according to land descriptors. The study used an analysis of primary data obtained from in-depth interviews and secondary data obtained from an agricultural database to identify and characterize large- and small-scale farming systems within the Vhembe district. The study examined the land resource namely farm size and land ownership, topography and soil description, rainfall and its variability and threats and hazards used under three different high value crop (HVC) commodities, macadamia nuts, mangos and avocado pears. The study further examined yield and income from farming as drivers of production that would ensure the sustainability of long-term food security at both national and household level. The study revealed that gender of farmers within the farming systems was predominantly (79%) male across all commodities. Age distribution results showed an aging population of farmers mostly (90%) above the age of 51. Communal land ownership was the dominant (74%) land ownership amongst participants. Yield is not solely dependent on farm size and requires consideration of a broader array of land management aspects. There was a strong, significant correlation between income and farm size. These factors have implications for sustainability of the two farming systems and illustrate how certain aspects of land as a driver of production such as land ownership, rainfall variability, yield and income from farming can impact sustainability.

Origin of the Domesticated Horticultural Species and Molecular Bases of Fruit Shape and Size Changes during the Domestication, Taking Tomato as an Example

Domestication of crop plants is the foundation of modern agriculture, which brings forth desirable changes in cultivated species that distinguish them from their wild relatives. This resulted in the origin of crop species at known geographical locations coinciding with the transition of human societies from hunter-gather to agrarian civilizations. Fruit size and shape are very important traits for horticulture industry, as well as for studying the domestication of the horticultural species. In this review, we have summarized the origin of some widely-grown horticultural crops and also the molecular bases of the fruit size and shape changes of the horticultural crops during the domestication, taking tomato as an example.

Pathogenic mechanisms and control strategies of Botrytis cinerea causing post-harvest decay in fruits and vegetables

Botrytis cinerea is a significant necrotrophic plant pathogen causing devastating diseases on more than 500 plant species,especially on fresh fruits and vegetables,resulting in the economic losses ranging from$10 billion to$100 billion worldwide.This fungal pathogen invades nearly all parts of plants including stems,leaves,flowers,fruits,and seeds at both pre-harvest and post-harvest stages.Due to its wide host range and the huge economic losses that it causes,extensive investigations have been carried out to effectively control this plant pathogen.It is beneficial for exploring the pathogenic mechanisms of B.cinerea to provide fundamental basis for control strategies.In recent years,tremendous progress has been made in understanding these pathogenic genes and regulatory pathways,as well as the control strategies of B.cinerea.Here,the current knowledge will be summarized in this review.

Geometry-based mass grading of mango fruits using image processing

Mango(Mangifera indica)is an important,and popular fruit in Bangladesh.However,the post-harvest processing of it is still mostly performed manually,a situation far from satisfactory,in terms of accuracy and throughput.To automate the grading of mangos(geometry and shape),we developed an image acquisition and processing system to extract projected area,perimeter,and roundness features.In this system,images were acquired using a XGA format color camera of 8-bit gray levels using fluorescent lighting.An image processing algorithm based on region based global thresholding color binarization,combined with median filter and morphological analysis was developed to classify mangos into one of three mass grades such as large,medium,and small.This system achieved an accuracy of 97% for projected area and Feret diameter,79% for perimeter,and 36% for roundness.To achieve a finer grading,two different grading features could be used in sequence.The image grading system is simple and efficient and can be considered a suitable first stage to mechanizing the commercial grading of mangos in Bangladesh.Moreover,the method has the potential to be applied to other crops with suitable adjustments.