盐胁迫对5个产地菘蓝幼苗光合特性及抗逆指标的影响

Effects of salt stress on photosynthetic characteristics and indexes of adverse circumstances-resistance of Isatis indigotica Fort. seedlings from five areas

[目的]本文旨在探究盐胁迫下不同产地菘蓝幼苗的生理响应规律,为菘蓝耐盐性材料的筛选与耐盐生理研究提供理论参考。[方法]以河北保定(HB)、内蒙古包头(NB)、辽宁铁岭(LT)、安徽亳州(AH)、山东滨州(SB)5个产地的菘蓝栽培居群为材料,采用避雨盆栽试验,分析不同浓度(0、50、100和150 mmol·L^(-1)NaCl)盐胁迫对各产地菘蓝幼苗生长、光合特性、保护酶系统及渗透调节物质的影响。[结果]盐胁迫下,LT和AH菘蓝幼苗含水率,叶片和根的鲜、干质量均呈下降趋势。HB和SB菘蓝幼苗的净光合速率(P_n)、气孔导度(G_s)、蒸腾速率(T_r)及叶绿素含量均随盐浓度的增加呈先升高后降低趋势,LT和AH菘蓝则随盐浓度的增加逐渐降低。随着盐浓度的升高,5个产地菘蓝幼苗丙二醛(MDA)含量均增加,超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、可溶性蛋白和脯氨酸含量均呈先上升后下降趋势,并在100 mmol·L^(-1)NaCl处理下达到最大值。[结论]不同产地菘蓝幼苗的耐盐性存在显著差异,100 mmol·L^(-1)盐浓度为菘蓝幼苗的极限耐受盐度。综合评价,河北保定和山东滨州菘蓝幼苗耐盐性强,内蒙古包头菘蓝的耐盐性次之,而安徽亳州和辽宁铁岭的菘蓝幼苗对盐的耐受性较差。

[ Objectives] This paper is to investigate the physiological responses of Isatis indigotica seedlings under salt stress, providing a theoretical basis for the screening of salt-tolerant materials and salt-tolerant physiology research. [ Methods ] In pot experiment, the I. indigotica seedlings from five areas [ Baoding, Hebei （ HB ） ; Baotou, Inner Mongolia （ NB ） ; Tieling, Liaoning （ LT ） ; Bozhou, Anhui （AH） ; Binzhou ,Shandong（SB） ] were used as research materials, and the influence of four concentrations NaC1 solution（ 0,50,100,150 mmol. L-~） on the growth, photosynthetic characteristics, protective enzyme system and osmoregulation substances was studied in I. indigotica seedlings. [ Results]The result showed that the fresh and dry weights of leaf and root and water content of 1. indigotica seedlings from LT and AH areas decreased under salt stress. The net photosynthetic rate, stomatal conductance, transpiration rate and chlorophyll content of I. indigotica seedlings from HB and SB areas were enhanced initially and then reduced under salt stress, while such indexes of seedlings from LT and AH areas declined remarkably with salt concentration increasing. With the improvement of NaC1 concentration,the activities of SOD and POD and osmoregulation substance contents such as soluble protein and proline of 1. indigotica seedlings from five areas increased first and decreased thereafter, peaking at 100 mmol. L-1 NaC1. Besides, MDA content increased gradually with the salt concentration increasing. [ Conclusions ] The salinity tolerance of I. indigotica seedlings from five areas was significantly different,and 100 mmol. L-l NaC1 was the salt tolerant limit of I. indigotica seedlings. By comprehensively evaluating, among five different areas, the I. indigotica seedlings from HB and SB had a strong tolerance and adaptability under salt stress,and the tolerance of seedlings from NB area was lower than that from above two areas. However, the seedlings of 1. indigotica from LT and AH areas were intolerant to salt stress.