Responses Of Different Genotypes Of Wheat To Soil Cadmium Pollution And Effect Of Bamboo Charcoal On Cadmium Accumulation In Wheat

Plants of 243 wheat genotypes were grown in a cadmium(Cd) contaminated field, the characteristics of grain Cd accumulation were comparied, in order to screen genotypes with high and low Cd grain accumulation, and for further study.. The agronomic characteristics of the selected wheat genotypes differing in Cd grain(high vs low) were examined by soil pot experiments, and Cd accumulation and distribution in plant organs at different growth stages were analyzed. Furthermore,bamboo biochar was applied to the soil to test its efficiency on plant Cd uptake reduction. It is hypothesized that wheat grain Cd content can be reduced significantly by using the low Cd accumulation wheat genotypes in combined with application of soil Cd passivator such as biochar to achieve the grain safety in production of wheat grown in areas with soil Cd pollution. The main results were as following:1. Great differences of grain Cd exist among the 243 wheat genotypes: and they were divided into 3 groups, namely high, medium and low grain Cd accumulation, accounting for 12.8%, 74.9%and 12.3%, respectively. Number of extreme genotypes(with high, or low grain Cd) is small.2. Through further field screening experiment, considering overall agronomic traits at filling and mature stages and Cd concentrations in different organs and Cd translocation ability, 4 genotypes were selected for further research: a high(146) and 3 low(115, 218 and 132) grain Cd accumulation.3. Wheat organ Cd concentrations increased with the increase of soil Cd content, but Cd distribution in the organs showed different features among the 4 genotypes. 132 showed low Cd accumulation character and 146 showed high Cd accumulation character. Low genotype 132 and high genotype 146 wheats showed contrasting Cd accumulation characteristics: shoot Cd concentration of132 was significantly lower than 146, and by contrast, the underground root Cd concentration was higher than 146.4. High soil Cd stress inhibited wheat growth, and appropriate bamboo biochar application rate could alleviate Cd poisoning for wheat. The low Cd genotype wheat 132 showed more tolerate to Cd stress than the high Cd genotype 146.5. Bamboo biochar suppressed wheat plant Cd uptake and accumulate, The distribution of Cd in wheat plant organs was largely controlled by its own genetic traits:146 wheat mainly accumulated Cdin root and stem sheath and grain, while mainly in the root and stem sheath for 132 wheat. For low Cd genotype wheat 132 grown in soil with extra addition of 2 mg · kg-1 Cd and 5% bamboo biochar application, its grain Cd content was even lower than that grown in blank treatment(no extra Cd addition, no bamboo biochar). Therefore, in Cd pollution soil, planting with low Cd genotype wheat(132) assisted with proper bamboo biochar application, grain Cd can effectively be reduced.