Carbon and nitrogen footprint of different peanut rotation systems in Hubei Province, China.

Clarifying carbon and nitrogen emissions of different peanut rotation planting system can provide an effective reference to achieve high yield, high efficiency, and low carbon and nitrogen emissions. Based on field surveys on agricultural inputs and field managements, we calculated the carbon footprint and nitrogen footprint of three planting modes (rape-peanut rotation, wheat-peanut rotation and peanut monoculture) in Huanggang, Hubei Province. The results showed that compared with wheat-peanut rotation, carbon emission per unit area of rape-peanut rotation decreased by 7.8%, carbon emission per unit net present value decreased by 36.9%, the nitrogen emission per unit area decreased by 12.5%, and nitrogen emission per unit net present value decreased by 41.9%. Compared with peanut monoculture, rape-peanut rotation reduced carbon and nitrogen emissions by 19.6% and 30.8%, respectively. The net income of rape-peanut rotation was 1.4 times as that of wheat-peanut rotation and 2.4 times as that of peanut monoculture. It is suggested that rape-peanut rotation could achieve the synergistic benefits of high yield and efficiency and low carbon and nitrogen emissions, which is conducive to the green, high quality, and high efficiency production of oil crops.

[Carbon footprint of wheat-summer direct-seeding peanut planting system in Shandong Pro-vince, China]. / 山东省小麦-夏直播花生种植体系碳足迹.

Clarifying the carbon emissions in wheat-summer direct-seeding peanut planting (W-P) system could help realize the synergistic effects of high yield and low carbon emissions. Based on whole life cycle method, we constructed a carbon footprint model to calculate the carbon emissions of W-P system. We found that the net income of W-P system was 71.2%-88.3% higher than that of wheat-maize rotation (W-M) system. The carbon emissions per unit area under W-P system was 6977.9-8018.5 kg·hm-2, being 6.2% higher than that of W-M system. The carbon emission of per net income under W-P system was 0.23-0.28 kg CO2-eq·yuan-1, which was 37.4%-44.1% lower than that of W-M system. Combining the net income and carbon emissions of per net income, W-P system could achieve synergistic effects of high yield and low carbon emissions, which would fulfill the targets of agricultural supply-side structural reform with optimizing supply, enhancing quality and efficiency, and increasing income of peasants.

[Effects of root cutting under different seedling conditions on root system distribution and senescence character of peanut].

The effects of root cutting on root system distribution and senescence character of peanut (Arachis hypogaea) under different seedling conditions were investigated by using the box culture method. The results showed that, with three types of peanut seedlings, including overgrowing, strong and week seedlings, root cutting all first restricted and then promoted the root system growth, especially promoted the root growth to deep soil. This effect was stronger on the overgrowing and strong seedlings, while relatively weaker on the weak seedlings. After root cutting, root activity, superoxide dismutase (SOD) and peroxidase (POD) activity all reduced at first, and then increased, compared with each control. The extents of decrease in root activity, SOD and POD activity were highest in the weak seedlings, lowest in the overgrowing seedlings, and moderate in the strong seedlings. However, in the later stage after root cutting, the extents of increase in root activity, SOD and POD activity were higher in the overgrowing and strong seedlings, than in the weak seedlings. Generally, root cutting could promote the root activity of peanut and delay the senescence.

[Effects of light quality on photosynthetic pigment contents and photosynthetic characteristics of peanut seedling leaves].

This study explored the effects of different light quality on photosynthetic pigment contents and photosynthetic characteristics of peanut (Qinhua 6) seedling leaves. The results showed that, compared with natural light, blue light (445-470 nm) could significantly improve the specific leaf area (SLA), chlorophyll a/b value and carotenoid content of peanut seedlings. Meanwhile, the net photosynthetic rate, stomatal conductance, and transpiration rate were higher, the intercellular CO2 content was lower, and the photosynthetic efficiency was improved significantly under blue light. Red light (610-660 nm) could improve the chlorophyll content significantly, and reduce SLA, chlorophyll a/b value and carotenoid content, with a lower photosynthetic efficiency than natural light. Green light (515-520 nm) and yellow light (590-595 nm) were not conducive to photosynthetic pigment accumulation of leaves, and significantly inhibited leaf photosynthesis of peanut seedlings.

[Effects of different cultivation modes on the leaf photosynthetic characteristics and yield of summer-sowing peanut].

Taking the Arachis hypogaea cv. 'Qinghua 7' as test material, a field experiment was conducted to study the effects of different cultivation modes on the leaf photosynthetic characteristics and yield of summer-sowing peanut after wheat harvest. As compared with conventional cultivation mode, high-yield protective cultivation mode promoted the leaf growth, significantly improved the leaf area index (LAI), and maintained a longer time of high LAI and chlorophyll content. Meanwhile, the net photosynthetic rate, stomatal conductance, and transpiration rate of functional leaves under high-yield protective cultivation mode were higher while the intercellular CO2 concentration was lower, which induced the photosynthetic efficiency of functional leaves being significantly improved. Therefore, under high-yield protective cultivation mode, the yield per peanut plant was higher, the pod yield increased significantly, and the economic coefficient improved obviously. Both film mulching and straw returning could also improve the leaf photosynthesis of summer-sowing peanut, and increase the peanut yield. It was suggested that high-yield protective cultivation mode could effectively alleviate the adverse factors of summer-sowing peanut, such as the short growth period and lower productivity per plant, being a practical high-yield cultivation mode of summer-sowing peanut.

[Physiological responses of different peanut (Arachis hypogaea L.) varieties to cadmium stress].

To have a deep understanding on the mechanisms of cadmium (Cd) toxicity on peanut plants is of theoretical and practical significances for the selection and utilization of Cd-resistant peanut germ plasm resources. With fourteen peanut varieties as test materials and taking the chlorophyll content of functional leaves, malondialdehyde (MDA) content and cell membrane permeability of roots and leaves, and oxidative vitality of roots at flowering stage as test physiological parameters, a sand culture experiment was conducted in an artificial climate chamber to investigate the physiological responses of different peanut varieties to six levels of Cd stress. The results showed that within the range of 0-60 mg Cd x L(-1) addition, the chlorophyll content of functional leaves and the oxidative vitality of roots decreased significantly with increasing Cd addition, while the MDA content and cell membrane permeability of leaves and roots were in adverse. The cell membrane permeability of roots and leaves was the most sensitive physiological parameter, while the chlorophyll content of functional leaves was the least sensitive one in the responses of peanut plant to Cd stress. In the linear regression equations describing the relationships between test physiological parameters and Cd concentrations in nutrient solution, the absolute value of slope (b)/intercept (a) ratio, /b/a/, could better describe the sensitivity of peanut plants to Cd stress. It was known from the integrative evaluation of /b/a/ values and the cluster analysis of sensitivity that among the fourteen peanut varieties, "Zhonghua-4", "Xiangnong-55" and "Xiangnong-3010-w" were highly sensitive to Cd stress (first grade), "Lainong-29", "Xiangnongxiaoguo-w2-7", "Fenghua-2", "Lainong-13", "Yuhua-15" and "Fenghua-3" were sensitive (second grade), "Xiangnong-312", "Qiyangxiaozi" and "Pingdu-01" were less sensitive (third grade), while "Huayu-20" and "Huayu-23" were insensitive (forth grade).

Hyperhomocysteinemia, deep vein thrombosis and vitamin B12 deficiency in a metformin-treated diabetic patient.

Vitamin B12 deficiency may be induced by long-term use of metformin, which may in turn lead to hyperhomocysteinemia. Thus, hyperhomocysteinemia may increase the risk of vascular thrombosis in diabetic patients, when metformin is used and a homozygous methylenetetrahydrofolate reductase (MTHFR) C677T mutation is present. We report a 65-year-old Taiwanese diabetic woman who was treated with metformin for 6 years and who had suffered from swelling of the left lower extremity for 3 months. Ascending venography confirmed the diagnosis of proximal deep vein thrombosis, while hyperhomocysteinemia, megaloblastic anemia caused by vitamin B12 deficiency, and a homozygous C677T mutation of the MTHFR gene were also found. She had no identifiable venous thrombotic risk factors other than hyperhomocysteinemia, which seemed to be caused by both MTHFR C677T homozygous mutation and vitamin B12 deficiency. With the substitution of insulin injection for metformin, short-term supplement of vitamin B12, and anticoagulant therapy for the deep vein thrombosis, her anemia and hyperhomocysteinemia recovered rapidly. The deep vein thrombosis also responded well. Our findings highly suggested the role of metformin in causing vitamin B12 deficiency, which may serve as an additional risk factor for venous thrombosis in diabetic patients. Our report also highlights the need to check vitamin B12 levels during metformin treatment.

[The effects of nitrogenous fertilizer on carbon metabolism characteristics of Glehnia littoralis].

The effects of different nitrogenous fertilizer on carbon metabolism in Glehnia littoralis were studied under the field condition. The results showed that the Sucrose Phosphat Synthase (SPS) activities and the content of soluble sugar in leaves showed the pattern of single peak curve during the growth period, and both highest level were similary appeared in the middle stage. The suitable rate of nitrogenous fertilizer can improve the SPS activities, the content of soluble sugar, the root Sucrose Synthase (SS) activities, and also kept low level of leaves soluble sugar in harvest. So it can be supply sufficient for assimilation of polysaccharide in the root as well as to increase the yield.