Response Of Seed Germination And Plant Growth To Saline Alkali Stress Of Cyperus Esculentus L.

To explore the adaptive characteristics of seed germination,plant growth and salinity stress under different reproductive periods.This test with"Cyperus esculentus L.Ⅰ"varieties for test material,by using two kinds of neutral salt（Na Cl and Na₂SO₄）and two kinds of alkaline salt（Na HCO₃and Na₂CO₃）respectively 2:1 ratio of salt and alkali stress,and using different concentrations of natural saline soil stress,under different salinity stress of C.esculentus seed germination,seedling morphological structure,physiological and ecological characteristics of a period of indicators.The adaptability and physiological response of C.esculentus to salinity stress provide scientific basis for the planting and promotion of C.esculentus in Xinjiang.The results show that:1.Effects of salt and alkali stress on seed germination of C.esculentus.With the increase of salt and alkali stress,the germination rate,germination potential,germination index and vigor index of C.esculentus seeds increased first and then decreased,reaching the maximum at 120 mmol?L^-1and 80 mmol?L^-1respectively.The length of germ and radicle showed a downward trend.The bud root than increased first and then decreased only under salt stress,and fluctuated under alkali stress.2.Effects of salt and alkali stress on growth and physiological characteristics of C.esculentus seedlings.Salt and alkali stress increased,seedling length,root length and biomass decreased.A high trend in proline,soluble sugar and CAT activity;It only increased SOD activity for the first time and then decreased,and reached the maximum under salt and alkali treatment at 80 mmol?L^-1and 40 mmol?L^-1,respectively.3.Effects of salt and alkali stress on photosynthetic characteristics of C.esculentus seedlings.With the increase of salt and alkali stress,the content of photosynthetic pigment in C.esculentus seedlings decreased,and Chl a,Car and Chl T increased slightly under low salt stress;Pn,Gs and Tr of all songs down,and the only Ci first decreased and then increased.In the fluorescence parameters,Fm,Fv/Fm,ΦPSⅡand q P showed a downward trend;F₀,Y（NPQ）and q N showed the trend of first rising and then falling;Only Y（NO）showed an upward trend.4.Effects of natural saline alkali stress on growth physiological indexes of C.esculentus.With the increase of the degree of natural saline alkali stress,the plant height,tillers,leaves and fresh and dry weight all showed a downward trend at the maturity stage.When the content of water-soluble salt is less than 2.75g·kg^-1,the underground part shows a promoting effect.At the same time,the contents of proline,soluble sugar,soluble protein and malondialdehyde in the leaves of C.esculentus were increasing,including malondialdehyde soluble sugar and soluble protein increased the content of water-soluble salt was 5.55g·kg^-1,and only SOD activity increased first and then decreased.5.Effects of natural saline alkali stress on photosynthetic indexes of phaseolus vulgaris.By increasing saline alkali stress,a trend in chlorophyil on the C.esculentus leaves showed a trend.In addition to the degree of saline alkali degree,the Pn,Gs,Tr and Ci showed a trend.Only the WUE showed an upward trend first and then a downward trend.In the fluorescence parameters,Fm,ΦPSⅡ,Fv/Fm showed a downward trend,while Y（NPQ）,Y（NO）and q N showed an upward trend.The results show that the treatment of excess light energy by C.esculentus transfers from fluorescence to heat dissipation to a certain extent.In conclusion,it showed that alkali stress caused greater damage to the germination of C.esculentus seedlings.When the concentration of neutral salt is less than 120 mmol?L^-1and the concentration of alkaline salt is less than 80 mmol?L^-1,the seeds of C.esculentus can germinate neatly and rapidly,but with the increase of concentration,the seeds of C.esculentus are gradually inhibited,moreover,the high concentration will lead to the inability of C.esculentus bean seeds to grow and develop normally,and the alkali stress causes more damage to seed germination and seedling growth and germination than salt stress.Under natural saline alkali stress,when the content of water-soluble salt is less than 4.16 g·kg^-1,the whole growth period of C.esculentus can grow better.When it exceeds 5.55 g·kg^-1,the growth and development of C.esculentus will be greatly affected.