【正文】
5d after seed planting (15d after seedling transplantation) %Salt/%RootShootLeaf 對(duì)根系生長(zhǎng)的影響 表5表明,與對(duì)照相比,隨著土壤鹽分濃度的增加,主根長(zhǎng)度逐漸下降,%%處理的差異未達(dá)顯著水平,%%處理的差異也未達(dá)顯著水平。MDA含量表現(xiàn)為隨著鹽分濃度的增加,MDA含量增加。%%NaCl的培養(yǎng)液中生長(zhǎng)狀況良好,葉綠素含量和根系活力有所提高,%%時(shí),葉綠素含量和根系活力逐漸下降;與對(duì)照相比,NaCl脅迫下幼苗的MDA水平降低。但由于有機(jī)肥有限,往往難以實(shí)現(xiàn)有機(jī)肥的足量施用。%、%、% %、%、%、%%,表現(xiàn)出與可溶性蛋白含量相反的態(tài)勢(shì)。表2 播種后45d(移栽后15d)海濱錦葵的株高、主莖葉齡和真葉大小Table 2 The plant height, leaf age, length and width of true leaves of K. virginica 45d after seed planting (15d after seedling transplantation)Salt/%plant height(cm)leaf age1st true leaf2nd true leafLength/cmWidth/cmLength/cmWidth/cm由表3可見(jiàn),隨著育苗基質(zhì)中鹽分濃度的增加,海濱錦葵各器官的鮮重逐漸下降。葉片生理活性的測(cè)定包括葉片可溶性蛋白、游離氨基酸、SOD、MDA含量或活性,測(cè)定方法參見(jiàn)《植物生理研究法》[14]。%、%、%、%%5個(gè)水平。salt stress。鹽堿地由于土壤含鹽量高,其種植作物(植物)主要面臨三個(gè)方面的問(wèn)題,一是出苗率、成苗率低;二是苗期營(yíng)養(yǎng)生長(zhǎng)不夠或者不當(dāng),難以搭起豐產(chǎn)架子;三是果實(shí)(籽粒)灌漿強(qiáng)度不夠或者灌漿速度慢??讖缴洗笙滦。蠌?cm。由圖2可見(jiàn),隨著土壤鹽分濃度的增加,海濱錦葵移栽后成活率呈現(xiàn)逐漸下降趨勢(shì),%、%、%、%%。與對(duì)照相比,%處理的根系總量有所增加,但未達(dá)顯著水平;%%處理相比,差異不顯著。與對(duì)照相比,%、%、% %、 、。林鶯[19]等也研究了NaCl對(duì)海濱錦葵光合作用特性的效應(yīng)以及鹽脅迫對(duì)海濱錦葵光合作用的響應(yīng),結(jié)果表明:鹽處理下海濱錦葵葉片的光合速率在處理的初期均下降,而且鹽濃度越高下降越明顯,當(dāng)其下降至最低點(diǎn)后又會(huì)有一定程度的回升,而后隨著處理時(shí)間的延長(zhǎng)又會(huì)出現(xiàn)持續(xù)的下降,處理鹽度越高光合速率下降得越明顯。在鹽堿地改造和作物栽培技術(shù)應(yīng)用時(shí),往往采用施用有機(jī)肥的方法來(lái)提高出苗率和促進(jìn)生長(zhǎng)發(fā)育。如圖5所示,育苗基質(zhì)中鹽分濃度的增加使得葉片中游離氨基酸的含量顯著增加。真葉長(zhǎng)、寬的測(cè)定結(jié)果進(jìn)一步表明,鹽分脅迫對(duì)葉片大小均產(chǎn)生了影響,%、%%三個(gè)處理的葉片長(zhǎng)和寬間的差異未達(dá)到顯著水平,%時(shí),葉片已接近脫落,無(wú)法進(jìn)行光合作用。待移栽后進(jìn)行根系和葉片生理活性、葉片光合性能的測(cè)定[13]。有機(jī)物基質(zhì)氮磷鉀有效養(yǎng)分總含量(N+P2O5+K2O)%。關(guān)鍵詞:海濱錦葵;鹽分脅迫;生長(zhǎng)發(fā)育;生理活性The Impact of Salt Stress on Salttolerant Bioenergy Plant K. virginica (L ) Presl.Abstract: The objective of this research was to make a probe into the effects of salt stress (0, %, %, % and %) on the growth and physiological characteristics of K. virginica seedlings so as to provide a solid base for the further research of seedling breeding. The seeds were sown into the pots of seedling plastic matrix containing the cultural mixture of organic substrate and conventional soil. Generally, when salt concentration in the mixture was less than %, the emergence rate was