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Improved lodging resistance is important for achieving high yield in irrigated environments. Higher planting density could be used to select genotypes with lodging resistance in irrigated environments. Cultivars carrying high plant density tolerance and high yield potential were recommended as leading cultivars for production as well as elite crossing parents for further increasing yield potential.
(Yonggui XIAO, Jianjun LIU, Haosheng LI, Xinyou CAO, Xianchun XIA, Zhon
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Wheat stripe rust caused by Puccinia striiformis f. sp. tritici (Pst) poses a great threat to wheat production worldwide. The rapid change in virulence of Pst leads to a loss of resistance in currently resistant wheat cultivars, which results in frequent disease epidemics. Therefore, a major focus is currently placed on investigating the molecular mechanisms underlying this rapid variation of pathogenicity and coevolving wheat resistance. Limited by the lack of a system for stable transformation of Pst and the difficulties in wheat transformation, it is not easy to generate deeper insights into the wheat-Pst interaction using established genetic methods. Nevertheless, considerable effort has been made to unravel the wheat-Pst interaction and significant progress is being made. Histology and cytology have revealed basic details of infection strategies and defense responses during wheat-Pst interactions, identified cellular components involved in wheat-Pst interactions, and have helped to elucidate their role in the infection process or in plant defense responses. Transcriptome and genome sequencing has revealed the molecular features and dynamics of the wheat-Pst pathosystem. Extensive molecular analyses have led to the identification of major components in the wheat resistance response and in Pst virulence. Studies of wheat-Pst interactions have now entered a new phase in which cellular and molecular approaches are being used. This review focuses on the cellular biology of wheat-Pst interactions and integrates the emerging data from molecular analyses with the histocytological observations.
This article discusses approaches to simultaneously increase grain yield and resource use efficiency in rice. Breeding nitrogen efficient cultivars without sacrificing rice yield potential, improving grain fill in later-flowering inferior spikelets and enhancing harvest index are three important approaches to achieving the dual goal of high grain yield and high resource use efficiency. Deeper root distribution and higher leaf photosynthetic N use efficiency at lower N rates could be used as selection criteria to develop N-efficient cultivars. Enhancing sink activity through increasing sugar-spikelet ratio at the heading time and enhancing the conversion efficiency from sucrose to starch though increasing the ratio of abscisic acid to ethylene in grains during grain fill could effectively improve grain fill in inferior spikelets. Several practices, such as post-anthesis controlled soil drying, an alternate wetting and moderate soil drying regime during the whole growing season, and non-flooded straw mulching cultivation, could substantially increase grain yield and water use efficiency, mainly via enhanced remobilization of stored carbon from vegetative tissues to grains and improved harvest index. Further research is needed to understand synergistic interaction between water and N on crop and soil and the mechanism underlying high resource use efficiency in high-yielding rice.
Foxtail millet is a minor yet important crop in some areas of the world, particularly northern China. It has strong adaptability to abiotic stresses, especially drought, and poor soil. It also has high nutritional value. Foxtail millet is rich in essential amino acids, fatty acids and minerals, and is considered to be one of the most digestible and non-allergenic grains available and has significant importance for human health. Given foxtail millet’s ability to adapt to abiotic stresses associated with climate change, it is more important than ever to develop breeding strategies that facilitate the increasing demand for high quality grain that better satisfies consumers. Here we review research on foxtail millet quality evaluation, appearance, cooking and eating quality at the phenotypic level. We review analysis of the main nutrients in foxtail millet, their relationships and the biochemical and genetic factors affecting their accumulation. In addition, we review past progress in breeding this regionally important crop, outline current status of breeding of foxtail millet, and make suggestions to improve grain quality.
With high rates of food and nonrenewable fossil fuel consumption worldwide, we are facing great challenges in ensuring food and energy security to satisfy the world population. Intercropping, as an important and sustainable cropping practice in agroecosystems, has been widely practiced around the world. Many studies have shown that some plants can deliver high yields when intercropped with other plants. Here, we review the biological mechanisms in improving resource utilization efficiency and illustrate the practical application of intercropping in ensuring food and energy security through improving production. Identifying suitable energy plants for marginal land, land not suitable for food crops growth, is an effective strategy to acquire high production of bioenergy, thus removing competition between the use of land for food and energy. The effective application of intercropping provides a potential pathway for production of food crops and energy plants by improving resource use efficiency and resistance to environmental stress.
Food security, the need to meet nutritional requirements, and four main problems for food protein security in China are analyzed. From the perspective of residents’ nutritional requirements and balanced dietary patterns, the conclusion is that food security in China is in essence dependent on protein production and security of supply and that fat and carbohydrates supply in China can reach self-sufficiency. Considering the situation of food protein production and consumption in China, policy suggestions are made, which could ensure a balanced supply and demand for food protein and food security in China.
Air pollution is becoming an increasingly important environmental concern due to its visible negative impact on human health. However, air pollution also affects agricultural crops or food security directly or indirectly, which has not so far received sufficient attention. In this overview, we take ozone (O 3 ) as an example to analyze the principles and extent of the impact of air pollution on food security in China based on a review of the literature. Current O 3 pollution shows a clear negative impact on food security, causing around a 10% yield decrease for major cereal crops according to a large number of field studies around the world. The mean yield decrease of winter wheat is predicted to be up to 20% in China, based on the projection of future ground-level O 3 concentration in 2020, if no pollution control measures are implemented. Strict mitigation of NO x and VOC s (two major precursors of O 3 ) emissions is crucial for reducing the negative impacts of ground-level O 3 on food security. Breeding new crop cultivars with tolerance to high ground-level O 3 should receive serious consideration in future research programs. In addition, integrated soil-crop system management will be an important option to mitigate the negative effects of elevated ground-level O 3 on cereal crop production and food quality.
China has successfully achieved food self-sufficiency over the past 50 years, however, with large inputs and losses. To meet the challenge of feeding a growing population with limited resources, many studies have explored options for improving productivity and efficiency of the food production. However, there have been few studies into the potential of reducing food loss along the whole food production-consumption chain. Here we review the literature on food waste in China. We briefly analyze (1) the drivers that influence levels of food waste in the food chain, (2) examine trends in the volumes and types of food wasted at different stages in the food chain, (3) assess the environmental and resource consequences of food waste in the food chain, and (4) evaluate the policy and stakeholder responses to the emerging challenges. It is concluded that reducing food loss and meeting food security in China requires a coherent institutional structure that promotes the synergistic outcomes of research, policy and education. Suggested key actions include (1) improving machinery and facility for sowing, harvesting, transportation and storage, which can reduce food loss by up to 50%, and (2) improving food waste recycling management, based on coupled food production and consumption systems.
Improved lodging resistance is important for achieving high yield in irrigated environments. This study was conducted to determine genotypic variation in lodging resistance and related morphological traits among winter wheat cultivars planted at two densities, and to identify key traits associated with lodging resistance. Lodging performance of 28 genotypes, including 24 released cultivars and four advanced lines, was evaluated at 250 plants per square meter and 500 plants per square meter in Shandong province during the 2008–2009 and 2009–2010 crop seasons. At the higher density, the average grain yield was 2.6% higher, even though lodging score rose by as much as 136%. The higher planting density increased lodging through increased leaf area index (LAI), plant height, center of gravity and length of basal internodes, and reduced grain weight per spike and diameter of the lower two stem internodes. LAI, center of gravity and diameter of first internodes, as the important indicators for lodging resistance, were significantly correlated with lodging score, with R= 0.62, 0.59 and −0.52 (P<0.01), respectively. Plant pushing resistance was significantly associated with diameter and length of the first internodes (R = 0.71–0.77, P<0.01), indicating it could be used to assess the strength of the lower stem. Higher planting density could be used to select genotypes with lodging resistance in irrigated environments. Cultivars carrying high plant density tolerance and high yield potential, such as Jimai 22 and Liangxing 66, were recommended as leading cultivars for production as well as elite crossing parents for further increasing yield potential in the Yellow and Huai Valleys Winter Wheat Zone in China.
Traditional agricultural practices have resulted in decreased soil fertility, shortage of water resources and deterioration of agricultural ecological environment, which are seriously affecting grain production. Conservation tillage (CT) research has been developed and applied in China since the 1960s and 1970s, and a series of development policies have been issued by the Chinese government. Recent research and application have shown that CT has positive effects on crop yields in China. According to the data from the Conservation Tillage Research Center (CTRC), Chinese Ministry of Agriculture (MOA), the mean crop yield increase can be at least 4% in double cropping systems in the North China Plain and 6% in single cropping systems in the dryland areas of North-east and North-west China. Crop yield increase was particularly significant in dryland areas and drought years. The mechanism for the yield increase in CT system can be attributed to enhanced soil water content and improved soil properties. Development strategies have been implemented to accelerate the adoption of CT in China.