The present study was undertaken to investigate the effect of Glomus mosseae on chlorophyll (Chl) content, Chl fluorescence parameters and chloroplast ultrastructure of beach plum seedlings under 2% NaCl stress. The results showed that compared to control, both Chl a and Chl b contents of NaCl + G. mosseae treatment were significantly lower during the salt stress, while Chl a/b ratio increased significantly. The increase of minimal fluorescence of darkadapted state (F 0 ), and the decrease of maximal fluorescence of dark-adapted state (F m ) and variable fluorescence (F v ) values were inhibited. The maximum quantum yield of PSII photochemistry (F v /F m ), the maximum energy transformation potential of PSII photochemistry (F v /F 0 ) and the effective quantum yield of PSII photochemistry (Ф PSII ) increased significantly, especially the latter two variables. The values of the photochemical quenching coefficient (q P ) and the nonphotochemical quenching (NPQ) were similar between G. mosseae inoculation and noninoculation. It could be concluded that G. mosseae inoculation could protect the photosystem II (PSII) of beach plum, enhance the efficiency of primary light energy conversion and improve the primitive response of photosynthesis under salinity stress. Meanwhile, G. mosseae inoculation was beneficial to maintain the integrity of thylakoid membrane and to protect the structure and function of chloroplast, which suggested that G. mosseae can alleviate the damage of NaCl stress to chloroplast.

Inbred lines are important germplasm in cauliflower breeding programs. To understand the genetic diversity and relationships of cauliflower inbred lines, the use of simple sequence repeat (SSR) markers will be of great value for parental line selection and breeding strategy design. In this study, the genetic diversity and relationships of 165 cauliflower inbred lines primarily derived from southeast China were assessed using SSR markers. Forty-three SSR markers were polymorphic across these inbred lines and generated a total of 111 alleles. The mean values of the number of alleles (Na), effective number of alleles (Ne), Shannon’s Information index (I), and polymorphism information content (PIC) per locus were 2.581, 1.599, 0.517 and 0.316, respectively. Genetic distance values among all pairs of the inbred lines varied from 0 to 0.67 with an average of 0.30. On the basis of genetic distance data estimated with the SSR markers, the 165 cauliflower inbred lines were classified into four main clusters (from group Ⅰ to group Ⅳ) by cluster analysis and four subpopulations (from POP 1 to POP 4) by structure analysis. The classification patterns of most cauliflower inbred lines were not consistent with their curd maturity, curd solidity or geographic origins. These results based on estimates by the SSR markers, suggested the genetic diversity of the 165 cauliflower inbred lines was relatively narrow. Therefore, pyramiding the valuable genes among different types of the cauliflower inbred lines is important to increase the genetic diversity to obtain desirable hybridization combinations. The information generated in this report will be useful for assessing germplasm and breeding in cauliflower.

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Relative germination percentage, relative germination rate, and relative germination index were studied using P1, P2, and 350 lines of a RIL population from the japonica rice (Oryza sativa L. japonica) cross of Bing 8979/C Bao. By means of mixed major gene plus polygene inheritance models, genetic analysis showed that relative germination percentage, relative germination rate, and relative germination index were controlled by two major genes plus polygenes. Both major genes and polygenes showed additive-epistatic effects. The additive effects were larger than epistatic effects in the two major genes. The heritability of major genes was larger than that of polygenes in all the three traits, indicating that the three traits investigated in the present study were mainly governed by major genes.