Fine mapping and marker-assisted selection (MAS) of a low glutelin content gene in rice

Rice with low glutelin content is suitable as functional food for patients affected with diabetes and kidney failure. The fine mapping of the gene(s) responsible for low glutelin content will provide information regarding the distribution of glutelin related genes in rice genome and will generate markers for the selection of low glutelin rice varieties. Following an SDS-PAGE screen of rice germplasm from Taihu Valley of China, Japonica selection W3660 is identified to be a novel mutant characterized with low glutelin content. For fine mapping the mutant gene for low glutelin content, F2 and F3 populations were derived from a cross between W3660 and Jingrennuo. SDS-PAGE analysis of the total endosperm protein showed that the low glutelin content trait was controlled by a single dominant nuclear gene. Genetic mapping, using SSRs, located this gene to chromosome 2, in the region between SSR2-001/SSR2-004 and RM1358. The dis- tances of the two markers to the target gene were 1.1 cM and 3.8 cM respectively. By semi-quantitative RT-PCR analysis, the transcripts of GluB4/GluB5 genes located within the region do not change. However, GluB5 gene located proximal to SSR2-001/SSR2-004 was specifically reduced. SSR profiles of seven Japonica varieties were compared with that of W3660 for loci in the relevant genetic region. The markers SSR2-004 and RM1358 were used for marker- assisted selection. The selection efficiencies of SSR2-004 and RM1358 were 96.8% and 92.7% respectively. This provides a standard starting point for the breeding of low glutelin content rice varieties in China.

Optimization of Agrobacterium tumefaciens-Mediated Immature Embryo Transformation System and Transformation of Glyphosate-Resistant Gene 2mG2-EPSPS in Maize(Zea mays L.)

Since maize is one of the most important cereal crops in the world,establishment of an efficient genetic transformation system is critical for its improvement.In the current study,several elite corn lines were tested for suitability of Agrobacterium tumefaciens-mediated transformation by using immature embryos as explants.Infection ability and efficiency of transformation of A.tumefaciens sp.strains EHA105 and LBA4404,different heat treatment times of immature embryos before infection,influence of L-cysteine addition in co-cultivation medium after transformation,and how different ways of selection and cultivation influence the efficiency of transformation were compared.Glyphosate-resistant gene 2mG2-EPSPS was transformed into several typical maize genotypes including 78599,Zong 31 and BA,under the optimum conditions.Results showed that the hypervirulent Agrobacterium tumefaciens sp.strain EHA105 was more infectious than LBA4404.Inclusion of L-cysteine（100 mg L-1） in co-cultivation medium,and heating of the immature embryos for 3 min prior to infection led to a significant increase in the transformation efficiency.Growth in resting medium for 4-10 d and delaying selection was beneficial to the survival of resistant calli.During induction of germination,adding a high concentration of 6-BA（5 mg L-1） and a low concentration of 2,4-D（0.2 mg L-1） to regeneration medium significantly enhanced germination percentage.Using the optimized transformation procedure,more than 800 transgenic plants were obtained from 78599,Zong 31 and BA.By spraying herbicide glyphosate on leaves of transgenic lines,we identified 66 primary glyphosate-resistant plants.The transformation efficiency was 8.2%.PCR and Southern-blot analyses confirmed the integration of the transgenes in the maize genome.

Identification of Wheat Canopy Structure Using Hyperspectral Data

Some winter wheat varieties were selected in this experiment. The results were as follows： 1） Leaf orientation value （LOV） and leaf area index （LAI） of wheat had different contributions to canopy spectral reflectance （CSR）. For example, LOV affected greatly canopy spectra more than LAI did in jointing stage, but LAI had a greater effect on CSR than LOV did after the ground was near to be covered completely. 2） Twenty treatments including different varieties and densities were arranged in this experiment, and the result of cluster analysis showed that all these treatments can be parted into four clusters according to LAI and LOV： varieties with erect leaves and low LAI （denoted as A）, varieties with erect leaves and high LAI （denoted as B）, varieties with horizontal leaves and low LAI （denoted as C）, varieties with horizontal leaves and high LAI （denoted as D）. Their CSR had difference in 400-700 nm and 700-1 150 nm at jointing stage, especially in different plant types. 3） There was obvious distribution difference among different clusters in scatter plot （X=△R890, Y=R890）, △R890 was the reflectance increment from jointing to booting stage. It was seen from the Y-axis direction that R890 of horizontal varieties were higher than the erect ones, and seen from the X-axis direction that the greater △R890 was, the lower LAI one within the same plant type varieties, which indicted that the combination of plant-type and the population magnitude can be initially identified by this method.

TRANSLATING THE MULTI-ACTOR APPROACH TO RESEARCH INTO PRACTICE USING A WORKSHOP APPROACH FOCUSING ON SPECIES MIXTURES

The EIP-Agri multiactor approach was exemplified during a 3-day workshop with 63 project participants from the EU H2020 funded project“Redesigning European cropping systems based on species MIXtures”.The objective was to share firsthand experience of participatory research among researchers who were mostly not familiar with this approach.Workshop participants were divided into smaller multidisciplinary groups and given the opportunity to interact with representatives from eight actor positions in the value chain of the agrifood cooperative Terrena located in Western France.The four stages of the workshop were:(1)key actor interviews,(2)sharing proposed solutions for overcoming barriers,and(3)developing possible interdisciplinary concepts.Expressions of frustration were recorded serving both as a motivation for group members to become more aware of the scientific concerns and practices of their colleagues,as well as a recognition that some researchers have better skills integrating qualitative approaches than others.Nevertheless,the workshop format was an effective way to gain a common understanding of the pertinent issues that need to be addressed to meet overall multiactorapproach objectives.Working with the actor networks was identified and emphasized as a means to overcome existing barriers between academia and practice in order to coproduce a shared vision of the benefits of species mixture benefits.

Soil microbes alleviate allelopathy of invasive plants

土壤微生物是这块地里的 allelopathic 效果的最重要的决定因素之一。然而，在生物侵略测试 allelopathy 的角色的大多数研究没考虑土壤微生物的角色。这里，我们测试了假设能降级的土壤微生物 allelochemicals 可以由改编随着时间的过去在土壤积累因此增加 allelochemicals 的降级并且在生物侵略减轻 allelopathic 效果。是期望，土壤微生物显著地减少了在九侵略植物种的八的叶 leachates 的 allelopathic 效果学习了。另外， Ageratina adenophora 在土壤显示出更低的 allelopathic 效果与长或在中间侵略历史比那些在有短侵略历史的土壤。侵略者的二主要 allelochemicals 与在土壤增加侵略历史更快被降级。相应地，土壤微生物的生物资源和活动与短侵略历史比在那在有长侵略历史的土壤是更高的。我们的结果显示土壤微生物可以逐渐地适应 Ageratina 的 allelochemicals 并且减轻它的 allelopathic 效果并且因此支持上述假设。当在生物侵略测试 allelopathy 或新奇武器假设的角色时，考虑土壤微生物的效果是必要的。