The Evolutionary Structure Research Of Dongdao4Resistance Alkali Adversity

This paper used paraffin section technology and optical microscopy photography technology to study Dongdao4rice seedlings which the different concentrations of Na2CO3stress in anatomical structure. The results showed that, Dongdao4rice seedlings which "the lower concentration" Na2CO3(5,10,15mmol/L) stress in anatomical structure showed some characteristics of alkali-resistance.Compared with the control group, Dongdao4rice seedlings (7) structure which5mmol/L Na2CO3stress was characterized by:The root epidermal cells became smaller. Cell diameter was about7.12μm. The exodermic cells arranged closely and neat. These cells had suberization. The endodermal cells became larger. Cell diameter was about6.99μm. The secondary wall thickened obviously. The leaves upper epidermis cuticula and lower epidermis cuticula thickened. The upper epidermis cuticula thickness was about3.73μm. The lower epidermis cuticula thickness was about3.79μm. The epidermal cells were small and neat. The bulliform cells depression deepened. Depth was about35.46μm. The leaves apparent structure plant print showed that the epidermal cell side wall sawtooth number increased. The epidermal cell set closely. The stoma closed. The stoma number in unit area increased. The stoma density was about212/mm2.Compared with the control group, Dongdao4rice seedlings (8) structure which10mmol/L Na2CO3stress was characterized by:The root epidermal cells became smaller. Cell diameter was about7.55μm. The exodermic cells arranged closely and neat. The endodermal cells became larger. Cell diameter was about6.79μm. The secondary wall thickened obviously. The leaves upper epidermis and lower epidermis cells were small. The bulliform cells depression deepened. Depth was about41.69μm. The leaves apparent structure plant print showed that epidermal cell side wall sawtooth number increased. The epidermal cell set closely. The stoma closed. The stoma number in unit area increased. The stoma density was about234/mm2.Compared with the control group, Dongdao4rice seedlings (9) structure which15mmol/L Na2CO3stress was characterized by:The root epidermal cells became smaller. Cell diameter was about7.09μm. The exodermic cells arranged closely and neat. The endodermal cells became smaller. Cell diameter was about6.33μm. The secondary wall thickened obviously. The leaves upper epidermis cuticula and lower epidermis cuticula were thickened. The upper epidermis cuticula thickness was about3.60μm. The lower epidermis cuticula thickness was about3.82μm. The epidermal cells were small and neat. The bulliform cells depression deepened. Depth was about34.42μm. The leaves apparent structure plant print showed that epidermal cell side wall sawtooth number increased. The epidermal cell set closely. The stoma closed. The stoma number in unit area increased. The stoma density was about264/mm2.This article found that Dongdao4rice seedlings which "the higher concentration" Na2CO3(20,25mmol/L) stress in anatomical structure showed more obvious characteristics of alkali-resistance.Compared with the control group, Dongdao4rice seedlings root epidermal cells which20,25mmol/L Na2CO3stress were smaller and set closely. Dongdao4rice seedlings (10) which20mmol/L Na2CO3stress root epidermal cells diameter was about6.55μm. The root epidermal cells diameter of Dongdao4rice seedlings (11) which25mmol/L Na2CO3stress was about6.72μm. The exodermis cell layer increased to three layers. The exodermic cells were smaller and had suberization. Cells arranged closely and neat. Cortex parenchyma had no aerenchyma and was composed of4-5cell layers. The cell secondary wall thickened obviously. The endodermal cells became smaller. No.10cell diameter was about5.65μm. No.11cell diameter was about5.45μm. The leaves upper epidermis cuticula and lower epidermis cuticula thickened obviously. The No.10leaves upper epidermis cuticula was about4.29μm. Its lower epidermis cuticula was about4.43μm. The No.11leaves upper epidermis cuticula was about4.32μm. Its lower epidermis cuticula was about4.51μm. The bulliform cells arranged closely. Depression deepened. No.10depth was about55.79μm. No.11depth was about55.13μm. The mesophyll cells arranged more tightly. The leaves apparent structure plant print showed that epidermal cell side wall sawtooth number increased. The epidermal cell set more closely. The stoma closed more rigorously. The stoma number in unit area increased. No.10stoma density was about359/mm2. No.11stoma density was about366/mm2.The above results showed that, Dongdao4rice seedlings which "the higher concentration" Na2CO3(20,25mmol/L) stress in anatomical structure showed more obvious characteristics of the alkali-resistance. It can better adapt to the growth environment of saline-alkali soil and played a key role to improve saline-alkali habitat after growing in saline-alkali soil. So we suggest selecting20mmol/L Na2CO3which "the higher concentration" alkali method in the breeding process. In order to increase its alkali-resistance ability after antagonism alkali stress cultivation in the Dongdao4rice seedling stage.