Evaluation of yield,stability and adaptability of national winter rapeseed regional trials in the upper Yangtze River region in 2017-2018

Rapeseed variety needs to be tested by regional trial in multiple sites for many years before being applied in market in China.Performants of rapeseed were affected by the interaction of sites and varieties.Evaluation of regional trials is very important for guiding rapeseed breeding.GGE(genotype main effects and genotypeenvironment interaction)biplot was used to evaluate yield,stability,adaptability,representativeness and discrimination of national winter rapeseed trials in the upper reaches of Yangtze River in 2017-2018.Results showed that the main effects of genotype(G),environment(E)and genotypeenvironment interaction(GE)were significant(P<0.01)for yield.Among them,E accounted for 46.95%total variation on average,G and GE accounted for 19.34%and 33.71%respectively.Eight varieties were found with high-yield,excellent stability and adaptability,including‘Yiyou 29’,‘Xiwang 920’,‘Liyouza 108’,‘Nanyou 546’,‘Dadi 195’,‘Jiayou 1’,‘Huayouza 28’and‘Yuhua 2’.Test sites included Nanchong,Mianyang,Wanzhou,Shuangliu and Chengdu in Sichuan Province and Zunyi together with Guiyang in Guizhou Province were selected for their excellent representativeness and discrimination.These results would provide theoretical basis for rapeseed breeding.

Advance in germplasm innovation and gene mining of high-oil maize

As one of the 3 worldwide major grain crops, maize is the main source of food, feed and edible vegetable oil. High-oil maize has been selectively bred for many years due to its high oil content and nutritional quality. However, compared with normal maize, the progress of high-oil maize breeding is hindered nowadays. Main problems are scarce of high-oil maize germplasm, conventional breeding methods, and slow genetic research progress on oil content and fatty acid composition. In this study, germplasm innovation and gene mining of high-oil maize were reviewed to provide theoretical reference for genetic breeding and utilization. Several high-oil basic populations have been developed after more than 100 years of selection, which have served as the unique resources for high-oil maize breeding. They have also been used to dissect genetic architecture of oil biosynthesis in maize kernel. Using linkage and association analyses, many QTLs and loci associated with oil content and fatty acid composition have been identified and mapped. In addition, some candidate genes for QTLs have been validated to regulate maize grain oil content and fatty acid composition. Prospect for high-oil maize was also discussed to provide knowledge about genetic mechanism of oil biosynthesis and improvement of kernel quality in maize.

Challenges and suggestions of Chinese rapeseed industry

Rapeseed industry is a central link in edible oil production, and plays a key role in edible oil safety. In order to resolve current problems of Chinese rapeseed industry, suggestions were put forward by combing present situation, prediction and practicable strategies of rapeseed industry. Challenges in Chinese rapeseed industry were analyzed, which included competition from international company; separation between breeding, popularization, and market demand; backward breeding model and R&D(research and development) in enterprise; lack of effective market regulation. Suggestions were made to improve rapeseed industry. First, comprehensive and rational modern rapeseed industry scientific development view should be applied in regional distribution of rapeseed production. Second, rapeseed breeding of China should coordinated and a platform should be formed for breeding innovation. Third, rapeseed multifunctional development and utilization need to be improved to meet the new consumption demand. At last, market supervision must be strengthened to ensure the sustainability and healthy development of seed industry. This paper provided theoretical references for rapeseed breeding and production applications, and established a solid foundation for rapeseed production and popularization in China.

Analysis of yield and quality characteristics of winter oilseed rape in China from 2001 to 2015: towards future breeding goals

The exciting outcomes of national regional trials have led to production and industrialization of China oilseed rape to a larger extent. To understand current trends of yield and quality traits of new varieties, data of national winter oilseed rape trials from 2001 to 2015 in 4 districts(upper, middle, lower Yangtze River and Huang-Huai River) was comprehensively analyzed. Results showed that average yield of new varieties of winter oilseed rape increased during the study period. In 2013, average yield of each district reached its highest level. Number of pod per plant reached its peak in 2011 and then declined rapidly in the next 4 years. Average number of seeds per pod did not significantly changed in any districts. Moreover, 1,000 seeds weight increased most obviously in Huang-Huai River district. After 2007, new oilseed rape varieties encountered the double-low quality(i.e., low erucic acid and low glucosinolate). In addition, oil content of new oilseed rape varieties increased over 15 years period and average oil content of all tested varieties during 2006-2015 was 42.96%, which was 2.38% higher than in 2005. Future breeding goals should be set to further improve yield, oil content, oil quality(such as high oleic acid and low saturated fatty acids), achieve full mechanization of oilseed rape production process and develop ideotypes.