Effect On Yield And Quality Of Cotton With Soil Waterloged And The Physiological Basis

In this experiment,according to practical production experience and meteorology date of field recently(reference occurrence regularity of natural flood disaster at bud stage and flowering and boll-setting period perennial).artificial simulation heavy rainfall environment of bud stage and flowering and boll-setting period to make intermittent waterlogging treatment.use the theory of optimizing boll formation. through cultivation way to study on basic principle of resistance flood and avoid the harmfulness of waterlogging disaster. Provide theoretical basis for cotton achieve the high-effeciency cultivation of stable yield under waterlogging. This experiments were carried out at the screened insectproof house of Nanjing Agricultural University in 2007, experiment station of jiangpu in 2008.The experiment matemial is Kemian 3. Four waterlogging treatments were established,Study on yield and fiber quality formation, spatiotemporal distribution of boll-setting physiological response of leaves under different waterlogging treatments. The main conclusion were as follows:1. Effection of waterlogging treatment to yield and quality of cotton.Number of boll-setting, boll weight, seed cotton yield and lint yield of increased design all waterlogging treatments under natural rainfall conditions all lower than control, but lint percentage was no difference. Seed cotton yield of W1 treatment was lower 7.61% than CK, W3 treatment was lower 27.04% than CK, in 2007. Seed cotton yield of W1 treatment was lower 7.27% than CK, W2 treatment was lower 12.09% than CK, W3 treatment was lower 31.81% than CK, in 2008. number of boll-setting and boll weight decrease of W3 treatment was the most serious, and yield loss. Cotton fiber quality of all treatments were inferior than control after waterlogging treatment. Double-stem cultivation treatment was established in this experiment, showed that the number of boll-setting and yield was significantly hyper than the conventional cotton under the same waterlogging treatment, boll weight and lint percentage was no significantly difference. The yield advantage of double-stem cotton showed on the superiority of boll quantity. The fibre quality of the double-stem cultivation treatment was overall superior to the conventional cultivation treatment, quality heterosis of that mainly presented uniformity, length and miclon of fibre were superior.2. the effect of spatiotemporal distribution on boll- setting of cotton under waterloggingThe squre-emerging intensity, number of available squares, intensity of boll-setting, rate of boll-setting and high quality boll number of cotton of all waterlogging treatments were all less than control in 2008.The squre-emerging intensity of W1 was lower 1.38×104·hm-2·d-1 than CK at one week after treatment, W2 was lower 1.55×104·hm-2·d-1 than CK, W3 was lower 2.58×104·hm-2·d-1 than CK. The boll-setting intensity of W1 was lower 0.26×104·hm-2·d-1 than CK, W2 was lower 0.73×104·hm-2·-1 than CK, W3 was lower 1.04×104·hm-2·d-1 than CK. the squre-emerging intensity, intensity of boll-setting, the final number of available squares of double-stem cultivation treatment were all significantly more than conventional cultivation cotton of the same waterlogging treatment.the boll number advantage of double-stem cotton was the most significant than conventional cotton under W3 treatment.3. The maximal increasing rates of cotton dry matter weight of all waterlogging treatments was lower than CK, the starting date of cotton dry matter weight speedy accumulation period were later, and the sustainable time of cotton dry matter weight speedy accumulation was longer. The maximal increasing rates of W1 cotton dry matter weight was lower 0.23g·d-1than CK, W2 was lower 0.58g·d-1 than CK, W3 was lower 1.22g·d-1 than CK. And during all the waterlogging treatments, especially effect of W3 treatment was the most serious. the maximal increasing rates of cotton dry matter weight of double-stem cultivation treatment were all significantly more than conventional cultivation cotton of the same waterlogging treatment. Compared to control, water potential of functional leaves decreased significantly of all waterlogging treatments. water potential of functional leaves of W1 was lower 26.67% than CK at the fourth day after treatment, W3 was lower 74.57% than CK. The third day after waterlogging, photosynthetic rate, stomatal conductance and transpitation rates of functional leaves and the leaves at the first sympodial node of the forth fruit branch were lower significantly than control, photosynthetic rate of functional leaves of W1 was lower 8.59% than CK, W2 was lower 10.22% than CK, W3 was lower 14.97% than CK; photosynthetic rate of the leaves at the first sympodial node of the forth fruit branch of W1 was lower 18.15% than CK, W2 was lower 23.46% than CK, W3 was lower 28.82% than CK. The fifth day after waterlogging treatment, content of MDA and proline, POD activity of functional leaves and the leaves at the first sympodial node of the forth fruit branch were higher significantly than control, MDA content of functional leaves of W1 was higher 12.43% than CK, W2 was higher 17.87% than CK, W3 was higher 26.89% than CK; MDA content of the leave at the first sympodial node of the forth fruit branch of W1 was higher 16.74% than CK, W2 was higher 25.04% than CK, W3 was higher 46.10% than CK. compare to these, content of chlorophyll and soluble protein, SOD activity were lower significantly than control. Waterlogging has significant injure effect on conventional cotton under all waterlogging treatments. Compare to conventional cotton, the double-stem cotton has more resistance to waterlogging.