[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.

[Research advances in plant lead tolerance and detoxification mechanism].

To have an overall understanding about the physiological mechanisms of plants in their lead (Pb) absorption, transportation, accumulation, and detoxification is the prerequisite of the phytoremediation of Pb-polluted soil. This paper reviewed the research advances in the mechanisms of plant Pb-adaptation and recovery, including the functions of cell wall and vacuole in Pb-inactivation and sequestration in plant cells, the effects of plant root exudates on Pb bioavailability, the roles of antioxidative enzymes dismutase (SOD), peroxidase (POD), catalase (CAT), glutathione reductase (GR), and ascorbate peroxidase (APX), and of antioxidants phytochelatins (PCs) and glutathione in Pb detoxification, and the expression and function of metallothionein and Pb-specific genes. The further researches on the plant's Pb-tolerance and detoxification mechanisms as well as the technologies for phytoremediation of Pb-contaminated environments were prospected.