[Effects of tobacco garlic crop rotation and intercropping on tobacco yield and rhizosphere soil phosphorus fractions].

A field plot experiment was conducted to investigate the tobacco yield and different forms of soil phosphorus under tobacco garlic crop rotation and intercropping patterns. The results showed that compared with tobacco monoculture, the tobacco yield and proportion of middle/high class of tobacco leaves to total leaves were significantly increased in tobacco garlic crop rotation and intercropping, and the rhizosphere soil available phosphorus contents were 1.3 and 1.7 times as high as that of tobacco monoculture at mature stage of lower leaf. For the inorganic phosphorus in rhizosphere and non-rhizosphere soil in different treatments, the contents of O-P and Fe-P were the highest, followed by Ca2-P and Al-P, and Ca8-P and Ca10-P were the lowest. Compared with tobacco monoculture and tobacco garlic crop intercropping, the Ca2-P concentration in rhizosphere soil under tobacco garlic crop rotation at mature stage of upper leaf, the Ca8-P concentration at mature stage of lower leaf, and the Ca10-P concentration at mature stage of middle leaf were lowest. The Al-P concentrations under tobacco garlic crop rotation and intercropping were 1.6 and 1.9 times, and 1.2 and 1.9 times as much as that under tobacco monoculture in rhizosphere soil at mature stages of lower leaf and middle leaf, respectively. The O-P concentrations in rhizosphere soil under tobacco garlic crop rotation and intercropping were significantly lower than that under tobacco monoculture. Compared with tobacco garlic crop intercropping, the tobacco garlic crop rotation could better improve tobacco yield and the proportion of high and middle class leaf by activating O-P, Ca10-P and resistant organic phosphorus in soil.

Association between the CYP1A1 T3801C polymorphism and risk of cancer: evidence from 268 case-control studies.

T3801C is a common polymorphism in CYP1A1, showing differences in its biological functions. Case-control studies have been performed to elucidate the role of T3801C in cancer, although the results are conflicting and heterogeneous. Hence, we performed a meta-analysis to investigate the association between cancer susceptibility and T3801C (55,963 cases and 76,631 controls from 268 studies) polymorphism in different inheritance models.We used odds ratios with 95% confidence intervals to assess the strength of the association. Overall, significantly increased cancer risk was observed in any genetic model (dominant model: odds ratio [OR]=1.14, 95% confidence interval [CI]=1.09­1.19; recessive model: OR=1.23, 95% CI=1.12­1.34; CC vs. TT: OR=1.31, 95% CI=1.19­1.45; TC vs. TT: OR=1.12, 95% CI=1.07­1.18; additive model: OR=1.14, 95% CI=1.09­1.19) when all eligible studies were pooled into the meta-analysis. In further stratified and sensitivity analyses, the elevated risk remained for subgroups of cervical cancer, head and neck cancer, hepatocellular cancer, leukemia, lung cancer, prostate cancer and breast cancer. In addition, significantly decreased colorectal cancer risk was also observed. In summary, this meta-analysis suggests that the participation of CYP1A1 T3801C is a genetic susceptibility for some cancer types.Moreover, our work also points out the importance of new studies for T3801C association in some cancer types, such as gallbladder cancer, Asians of acute myeloid leukemia, and thyroid cancer, where at least some of the covariates responsible for heterogeneity could be controlled, to obtain a more conclusive understanding about the function of the CYP1A1 T3801C polymorphism in cancer development.

Association between the XPG Asp1104His and XPF Arg415Gln polymorphisms and risk of cancer: a meta-analysis.

BACKGROUND: The XPG (xeroderma pigmentosum type G) Asp1104His and XPF (xeroderma pigmentosum type F) Arg415Gln polymorphisms had been implicated in cancer susceptibility. The previous published data on the association between XPG Asp1104His and XPF Arg415Gln polymorphisms and cancer risk remained controversial. METHODOLOGY/PRINCIPAL FINDINGS: To derive a more precise estimation of the association between the XPG Asp1104His and XPF Arg415Gln polymorphisms and overall cancer risk, we performed a meta-analysis to investigate the association between cancer susceptibility and XPG Asp1104His (32,162 cases and 39,858 controls from 66 studies) and XPF Arg415Gln polymorphisms (17,864 cases and 20,578 controls from 32 studies) in different inheritance models. We used odds ratios with 95% confidence intervals to assess the strength of the association. Overall, significantly elevated cancer risk was found when all studies were pooled into the meta-analysis of XPG Asp1104His (dominant model: OR = 1.05, 95% CI = 1.00-1.10; Asp/His vs. Asp/Asp: OR = 1.06, 95% CI = 1.01-1.11). In the further stratified and sensitivity analyses, significantly decreased lung cancer risk was found for XPF Arg415Gln (dominant model: OR = 0.82, 95% CI = 0.71-0.96; Arg/Gln versus Arg/Arg: OR = 0.83, 95% CI = 0.71-0.97; additive model: OR = 0.83, 95% CI = 0.72-0.95) and significantly increased other cancer risk was found among hospital-based studies for XPG Asp1104His (dominant model: OR = 1.23, 95% CI = 1.02-1.49). CONCLUSIONS/SIGNIFICANCE: In summary, this meta-analysis suggests that XPF Arg415Gln polymorphism may be associated with decreased lung cancer risk and XPG Asp1104His may be a low-penetrant risk factor in some cancers development. And larger scale primary studies are required to further evaluate the interaction of XPG Asp1104His and XPF Arg415Gln polymorphisms and cancer risk in specific populations.

[Differences in phosphorus utilization efficiency among wheat cultivars].

A pot experiment was conducted to study the differences in the biomass, phosphorus concentration, phosphorus use efficiency for dry matter, and phosphorus use efficiency for grain yield among different wheat cultivars under low phosphorus supply, aimed to screen the wheat varieties with high phosphorus use efficiency. For the test cultivars, their biomass per plant at tillering, jointing, flowering, and maturing stages was 0.46-1.09, 0.85-2.10, 3.00-7.00, and 3.85-12.88 g, and their phosphorus concentration was 2.21-4.26, 2.38-4.42, 2.44-4.96, and 1.30-5.09 mg x g(-1), respectively. From tillering to maturing stages, the phosphorus accumulation in plant and the phosphorus use efficiency for dry matter displayed a decreasing effect on the biomass formation. Significant differences were observed in the phosphorus use efficiency for dry matter (tillering stage CV = 16.3%, jointing stage CV = 15.0%, and flowering stage CV = 13.3%) and in the phosphorus use efficiency for grain yield (maturing stage CV = 20.5%) among the cultivars. The cultivars CD1158-7 and Sheng A3 Yi 034 had higher phosphorus use efficiency for dry matter and phosphorus use efficiency for grain yield, while the Yu 02321 was in adverse. The phosphorus concentration in the cultivars with high phosphorus use efficiency was significantly lower than that in the cultivars with low phosphorus use efficiency, and the grain yield of CD1158-7 and Sheng A3 Yi 03-4 was 0.98 times and 0.78 times higher than that of Yu 02321.

[Genotype difference in nitrogen utilization efficiency of wheat].

A pot experiment with 130 wheat cultivars was conducted to study their genotype difference in biomass per plant, nitrogen accumulation, and nitrogen production efficiency under the same level of nitrogen supply, aimed to screen the high efficiency nitrogen-utilizing wheat genotypes. The results showed that the biomass per plant of the cultivars at jointing, heading, and maturing stages was within the ranges of 1.06-3.08 g, 1.88-9.05 g, and 2.64-13.75 g, respectively, and the yield per plant was 1.38-9.90 g. The nitrogen dry matter production efficiency was 25.62-65.41 g x g(-1) N (F = 5.099 * *) at jointing stage and 35.79 - 88.70 g x g(-1) N (F = 5.325 * *) at heading stage, and the nitrogen production efficiency of grain yield was 19.06-38.54 g x g(-1) N (F = 4.669 * *) at maturing stage. There were significant differences in nitrogen dry matter production efficiency (jointing stage, F = 637.941 * *; heading stage, F = 201.173 * *) and nitrogen grain yield production efficiency (maturing stage, F = 443.450 * *), and also, in biomass accumulation among the cultivars, but no significant differences in tiller number and effective tiller number. The wheat genotypes with high nitrogen utilization efficiency had the characteristics of less ineffective tiller, high nitrogen utilization before heading stage, and high effective nitrogen absorption and reuse capability at heading and maturing stage. The grain yields of high nitrogen efficiency genotypes Sheng CXK027-4 and Liangmai 4 were 2.44 times and 1.86 times higher than those of low nitrogen use efficiency genotype 694, and the nitrogen accumulation in grain yields was 2.06 times and 1.81 times higher than that of low nitrogen use efficiency genotype 694, respectively.