The yield of maize (Zea mays L.) is affected by the plant architecture which is associated with the distribution of light within canopy and utilization of solar energy within population. Plant architecture of maize is mainly characterized by leaf angle (LA) and leaf space (LS). To analyze the genetic mechanism of LA and LS above ear position in maize, a genetic linkage map composed of 212 simple sequence repeat markers was constructed based on a F 2 population derived from the cross between the compact inbred line CY5 and the expanded inbred line YL106. The map spanned 1,153.39 cM in length with an average interval of 5.44 cM. By using the inclusive composite interval mapping method, QTLs for LA and LS above ear position were identified based on two field mapping populations consisted of 144 F 2:3 families in three environments and 144 F 4 families, respectively. In F 2:3 population, three consistent QTLs qSecLA1a, qThiLA1a, and qThiLS7 were detected in both single-environment analysis and joint-environment analysis. The qSecLA1a between bnlg1803 and bnlg1007 on chromosome 1.02 explained 26.99 and 18.51 % of the phenotypic variation, qThiLA1a between bnlg1803 and bnlg1007 on chromosome 1.02 explained 24.14 and 22.00 % of the phenotypic variation and qThiLS7 between bnlg1305 and umc1787 on chromosome 7.02/7.03 explained 13.77 and 9.96 % of the phenotypic variation in single environment analysis while the three QTLs explained 29.10, 31.86 and 11.20 % of the phenotypic variation, respectively in joint environment analysis. Moreover, there were major QTLs near bnlg1803 on chromosome 1 for SecLA and ThiLA stably expressing in F 2:3 and F 4 generations. The results of this study could provide references for genetic modification and molecular marker-assisted selection for LA and LS in maize.

Elucidating the correlations among maize (Zea mays L.) brace‐root traits and identifying the quantitative trait loci (QTL) that control the traits are important for genetic improvement of brace‐root traits. Two maize inbred lines, Yi17 (well‐developed root system) and Yi16 (poorly developed root system), an F2 population derived from their cross containing 276 individuals, and an F2:3 population containing 241 families were used to analyze the correlations among brace‐root traits and determine the QTL for brace‐root traits at Xiema and Hechuan in 2014 and 2015. All brace‐root traits were highly significantly correlated with each other. In particular, brace‐root diameter was highly correlated with brace‐root fresh weight (r = 0.730), brace‐root dry weight (r = 0.729), root fresh weight (r = 0.734), and root dry weight (r = 0.754). A total of 212 simple sequence repeat (SSR) markers were used to develop a genetic map based on the F2 population. The total length of the genetic map was 1558.9 cM, with a mean interval of 7.35 cM between adjacent markers. Ninety‐three QTL controlling the brace‐root traits were detected in generations F2 at Xiema in 2014 and F2:3 at Xiema and Hechuan in 2015. However, only two consistent major QTL were identified in F2:3 generation—qBRTN8b for brace‐root tier number and qBRD8b for brace‐root diameter. The qBRTN8b was located in the mmc0181 to bnlg1031 interval (bin 8.06) on chromosome 8, which explained 32.64% (at Xiema) and 16.18% (at Hechuan) of phenotypic variation. The qBRD8b was mapped in the umc2367 to umc1846 interval (bin 8.05) on chromosome 8, which explained 14.28% (at Xiema) and 10.41% (at Hechuan) of phenotypic variation. Moreover, three new important chromosomal regions harboring QTL for brace‐root traits were detected—bins 5.04, 6.06, and 8.05 to 8.06. These results could provide a very important reference for evaluating root traits under field conditions and for fine mapping QTL of brace‐root traits in maize.

In our previous study, two major quantitative trait loci (QTLs) for kernel anthocyanin content in maize (Zea mays L.) were mapped on chromosome 6 and chromosome 10 by using two related F2:3 populations derived from crosses of ‘Mu6’ × ‘Super Dark Maize’ (SDM) and ‘Mo17’ × SDM. In this study, two sets of near isogenic lines, MuS‐BC4F3 and MoS‐BC4F3, were developed and used to further map the two QTLs and analyze the epsitasis between the two QTLs. GEN6 was further mapped in the interval S8‐umc1105 on chromosome 6 for MuS‐BC4F3 and S8 to mmc0523 on chromosome 6 for MoS‐BC4F3. GEN10 was further mapped in the interval IDP8526 to S44 on chromosome 10 for MuS‐BC4F3 and bnlg1028 to IDP8526 on chromosome 10 for MoS‐BC4F3. GEN6 and GEN10 controlled both kernel anthocyanin content and cob anthocyanin content. The epistasis between GEN6 and GEN10 was a coadaptive interaction. The anthocyanin content is likely to greatly increase when GEN6 and GEN10 coexist. Additive × dominant (AD) effects were the largest of all the epistatic effects for kernel anthocyanin content; additive × additive (AA) effects were the largest for cob anthocyanin content. These results could provide a new reference for anthocyanin's genetic mechanism and high anthocyanin breeding in maize.

The response of Iris pseudacorus to the introduction of earthworms and to a variety of substrates in constructed wetland systems was investigated under greenhouse conditions. The growth of I. pseudacorus was influenced by the presence of earthworms and the type of substrate. Plants grown on a sand substrate had the fewest seedlings and the smallest plant size. Because the sand substrate started with the lowest nutritional value, the addition of earthworms resulted in the largest increase in fresh and dry weights of I. pseudacorus, when compared with the other pairs of substrate treatments, with or without earthworms. The addition of earthworms increased pod production in I. pseudacorus, especially on substrates of mixed sand and soil, and with mixed sand and organic matter. Pod production in I. pseudacorus pots with earthworms varied by substrate.

Concentrations of 6 kinds of phthalic acid esters (PAEs) in sewage sludge from 20 typical municipal wastewater treatment plants (WWTPs) in Jiangsu province were determined by gas chromatography-mass spectrometry (GC-MS) . The results shows that the sewage sludge samples contain phthalic acid ester compounds, which total content of phthalic acid esters ( PAEs) range from 15.126 to 71.107 ug/g (dry sludge). The content of diethylhexyl phthalate (DEHP) is the highest, which amounts more than 80% of total phthalic acid esters (PAE); the content of dimethyl phthalate (DMP) is low ,which is less than 1.0 ug/g;Diethyl phthalate (DEP), dibutyl phthalate (DBP) and benzyl butyl phthalate (BBP) are detected in each sludge sample, but which content display greater difference; Dioctyl phthalate (DOP) in most cities is not detected.