Studies on hypersaline-tolerant white-rot fungi IV: effects of Mn 2+ and NH 4 + on manganese peroxidase production and Poly R-478 decolorization by the marine isolate Phlebia sp. MG-60 under saline conditions

Manganese peroxidase (MnP) production by Phlebia sp. MG-60 is strongly regulated by Mn²⁺ and NH₄⁺ at various sea salt incubation conditions. Extra-added Mn²⁺ and NH₄⁺ obviously inhibited MnP production, but sea salts relieved the inhibition partially or completely. Three media were prepared: Kirk medium with addition of 0%–5% sea salts (KS medium), a high level of Mn²⁺ (300mg/l) in KS medium (HM-KS medium), and a high level of NH₄⁺ (430mg/l) in KS medium (HN-KS medium). Without addition of sea salts, the dye Poly R-478 was significantly decolorized by low MnP activity (about 200U/l) and a low level of laccase activity (about 100U/l) in KS and HM-KS media. In the cultures in which laccase activity was almost completely inhibited by 3% and 5% sea salts, MnP activity higher than 400U/l was necessary for Poly R-478 decolorization in all of the three media. We first report the linear correlation of MnP activity and decolorization of Poly R-478 under saline conditions and the effect of laccase on this relation.     

8个掖478玉米近缘系主要农艺性状的配合力及遗传分析

选用丹340、郑22、868作父本,8个掖478自交系近缘系作母本,采用NCⅡ设计组配24个杂交组合,对24个F1的9个主要农艺性状进行了一般配合力、特殊配合力及遗传参数分析。结果表明,24个组合9个性状的F检验均达显著或极显著水平。3个父本自交系9个性状的一般配合力存在极显著差异。8个掖478母本自交系各性状一般配合力方差除株高、穗位极显著外,其余7个性状均未达显著水平。株高、穗位、单株产量、穗行数、行粒数、百粒重和轴粗表现主要受加性基因效应影响,穗长、茎粗受加性、非加性基因效应共同影响。     

不同密度下玉米掖478衍生系产量相关性状的配合力分析

用掖478衍生系K22、沈5003、U8112、早48和郑58为被测系,以Mo17、齐319、丹340和昌7-2为测验系,基于NCII设计得到20个杂交组合,在高、低种植密度下对产量相关性状进行配合力分析。结果表明,掖478衍生系及其杂交种的产量性状受密度、基因型等影响。早48和郑58的4个以上穗部性状的一般配合力在高密度下效应值较高,且高于低密度下的效应值。早48×丹340和郑58×齐319在高密度下单穗粒重最高且多数性状特殊配合力均为正效应。早48和郑58在高密度下综合表现较其他衍生系更好,在该区域耐密高产育种中可以重点利用。