Physiological Responses Of Aronia Melanocarpa To Stress

Aronia melanocarpa(Michx.)Elliott is a perennial shrub belonging to the genus Photinia of Rosaceae.It is a valuable tree species with edible,medicinal,garden and ecological values.In 2017,Aronia melanocarpa was introduced and cultivated as an emerging economic tree species in Jingyuan County,Ningxia.Although it has been promoted on a certain scale,there are no reports on its growth performance,stress resistance and fruit nutritional composition in Ningxia.In this study,two elite varieties,’Fukangyuan I’ and’Heibaoshi’,were observed for phenological traits,and evaluated for fruit nutrients in different adversity stresses.The physiological characteristics of stress resistance were studied by pot control method.The results were as follows:(1)The growth period of the two species of Aronia melanocarpa in Jingyuan is about 170-180 days.The leaves and buds begin to appear in early April.The flowering period lasts about 30 days,and the fruit growth period is about 110 days.The leaf development and budding periods of ’Fukangyuan I’ are about 10 days later of ’Heibaoshi’;the fruits of the two species of Aronia melanocarpa with contain 6 essential amino acids,and the calcium content of ’Heibaoshi’ is higher than that of ’Fukangyuan I’.The contents of β-carotene,vitamin C,vitamin B6,manganese and crude protein of ’Heibaoshi’ is lower than those of’Fukangyuan I".(2)With the deepening of the drought,the growth of new shoots,soluble protein,proline content,superoxide disproportionation Enzyme(SOD),peroxidase(POD)and catalase(CAT)activities showed a downward trend.The drought resistance of ’Fukangyuan I’ is stronger than that of ’Heibaoshi’,and it can withstand moderate drought(45%Φ f-50%Φ f),and ’Heibaoshi’ can withstand mild drought(60%Φ f-65%Φf).(3)As the degree of flooding deepened,the new shoots of ’Fukangyuan I’ and ’Heibaoshi’showed a downward trend.The root-to-shoot ratio,soluble protein,proline content and SOD,POD,CAT activities increased first and then decreased.And reached the maximum value under mild flooding treatment that showed ’Fukangyuan I’ and ’Heibaoshi’ can withstand mild flooding and can reach 30 days.(4)With the degree of salt stress deepens,the soluble sugar and proline content of’Heibaoshi’ and ’Fukangyuan I’ showed an upward trend,while the soluble protein content showed a downward trend;the activity of protective enzymes first rises and then declines.The salt tolerance of the two varieties is ’Fukangyuan I’>’Heibaoshi’,the salt tolerance of’Heibaoshi’ is 0.5%,and the salt tolerance of ’Fukangyuan I’ is 1%.