菜心耐羟脯氨酸初选系的耐热性

Heat tolerance Characteristics of a Hydroxyproline-resistant Line of Brassica campestris L . ssp. chinensis var. utilis Tsen et Lee

摘要:

分析了离体筛选出的一个菜心耐羟脯氨酸选择系的脯氨酸含量和耐热性。Hypr01比原品种六十天特青有较高的游离脯氨酸含量;35℃热胁迫下Hypr01中有显著的游离脯氨酸含量增加,为六十天特青的4倍和耐热品种四九菜心的近2倍。与对照相比,在35℃下连续培养的Hypr01愈伤组织表现出更强的活力和根的分化能力,鲜重增量明显加大;相对电解质渗出率、愈伤组织褐变程度和MDA含量低;SOD、CAT活性较高。在人工气候箱模拟栽培高温逆境下,Hypr01再生苗生长优于未经选择的六十天特青,并具较低的电解质渗出率和较高的鲜重增长,说明有较强的耐热性。

Abstract:

Proline (Pro) content and heat tolerance were determined in a hydroxyproline-resistant line Hypr01 selected in vitro from seedlings of Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee. Hypr01 had higher content of free Pro than the original cultivar Liushitianteqing. A greater increase of free Pro content could be found in Hypr01 under heat stress at 35℃, which was 4 times as much as that in Liushitianteqing and nearly 2 times in heat tolerant cultivar Sijiu. Compared to the control, the callus induced from Hypr01 shoots showed vigorous，root differentiation ability and high fresh weight increment when cultured under successive stress at 35℃． Under such condition，the relative electrolyte leakage，callus browning rate and the content of MDA in Hypr01 were significant lower，but the activities of SOD and CAT in Hypr01 was higher．The plantlets regenerated from Hpyr01 grew better than those from Liushitianteqing under a heat stress condition(35℃ by day and 25℃ by night both for 12 h) in phytotron，and had lower electrolyte leakage and higher fresh weight increment，which indicated a greater heat tolerance.