| Photosynthesis is essential for crop yield formation, this study employed 58 wheat cultivars as materials, identified the allelic variation of vernalization gene Vrn1 and photoperiod gene Ppd-D1 by using STS markers, analyzed the effects of allelic variation of Vrn1 and Ppd-D1 on photosynthetic traits at filling stage and yield traits under full irrigation and water stress conditions; using 42 introduced winter wheat germplasm as materials, evaluated their photosynthetic efficiency related traits, preliminary analyzed the use of spectral reflectance parameters on evaluating on photosynthetic efficiency, to promote the screening and innovation of wheat germplasm with high photosynthetic efficiency.The main results are as follows:1. Marker tests of 58 varieties showed that, all the wheat cultivars carried recessive vrn-A1, the frequency of dominant Vrn-B1 and Vrn-D1 was 8.62% and 43.10%, indicating that most of the cultivars were winter varieties; the frequency of Ppd-D1 a was 91.34%, indicating that most varieties were photoperiod sensitive types. These cultivars were grouped based on allelic variation of Vrn-B1 and Vrn-D1, then their effects on photosynthetic efficiency were evaluated. The results showed that, under water stress condition, Vrn-B1 had significant effects on net photosynthetic rate, but no significant effect on yield traits under both water stress and full irrigation conditions; under full irrigation condition, vrn-D1 had significant effects on net photosynthetic rate, transpiration efficiency and grain yield per plant, under water stress condition, the intercellular CO2 concentration and grain yield per plant of vrn-D1 were significant higher than that of Vrn-D1. In summary, cultivars with vrn-D1 were with higher photosynthetic capacity and yield, which could be focused in wheat breeding.2. Under two water treatments, compared with Jinmai47, the photosynthetic physiological traits, dry matter accumulation and transfer, and yield traits of 42 introduced wheat germplasm were measured and compared. The results indicated that, most introduced germplasm had significantly higher photosynthetic characteristics and dry matter transfer parameters than the control, while their yield traits were lower than the control or no significant difference with the control; the chlorophyll levels of most introduced germplasm were higher than the control, and affected less by water stress. Under well-watered treatment, photosynthetic traits, chlorophyll content and dry matter metastasis of four and two germplasm were significantly higher than Jinmai47 at heading and filling stages, respectively, and one germplasm showed better at two stages; under water stressed treatment, photosynthetic traits, chlorophyll content and dry matter metastasis of two and four germplasm were significantly higher than Jinmai47 at heading and filling stages, respectively, and two accessions showed significantly higher than Jinmai47. In addition, comparison by drought resistance coefficient suggested, germplasm No. 3 could maintain relatively stable photosynthetic performance under water stressed treatment at filling stage, and the yield of germplasm No.12 was less affected by water stress. The germplasm with drought-resistant and higher photosynthetic efficiency have potential to be applied in wheat breeding.3. Employed 42 introduced germplasm to be as materials, the correlations between canopy spectral reflectance parameters, canopy temperature depression with photosynthetic physiological traits, dry matter accumulation and the yield traits under different water treatments were analysed. The results found that, there were significant correlations between spectral reflectance parameters derived from 550 nm ~ 675 nm wavelength with vegetation indices and traits. Under full irrigation condition, there was significant and positive correlation between(R750-R550)/(R750+R550) and the accumulated quantity of dry matter; under water stress condition, there was significant positive correlation between(R750-R550)/(R750+R550) and R750/R675 with net photosynthetic rate, it may be used as an indicator for screening wheat germplasm with high photosynthetic efficiency.In summary, the result showed that some introduced germplasm performed well in photosynthetic physiological traits, dry matter accumulation and transfer, and these accessions could be used as materials in wheat genetic improvement and breeding for photosynthetic efficiency, and, canopy reflectance spectra parameters could be used in screening wheat germplasm for photosynthetic efficiency. |
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