施钾量与密度对胡麻木质素合成积累及抗倒伏特性的调控

为探索胡麻木质素代谢与抗倒伏性能对钾肥和密度的响应规律,以‘陇亚11号’胡麻为供试材料,设置施钾(K₂O)量(0 kg·hm^-2、60 kg·hm^-2、90 kg·hm^-2 分别记作K0、K1、K2)和种植密度(6.0×10⁶ 株·hm^-2、7.5×10⁶ 株·hm^-2、9.0×10⁶ 株·hm^-2分别记作D1、D2、D3)二因素随机区组试验,研究施钾和密度对胡麻茎秆抗折力、抗倒伏指数、木质素代谢关键酶活性、木质素含量及分布和产量构成的影响。结果表明,随着胡麻生育时期的推进,PAL、TAL活性迅速增加,在青果期达到最大值;青果期,各钾肥水平PAL、TAL活性较K0水平显著升高2.90%～16.78%、12.39%～33.72%,中密度D2水平下木质素含量较其他密度水平显著增加1.32%～14.01%,茎秆抗折力和抗倒伏指数均达到最大值,与其他密度水平差异显著;密度/钾肥...     

黔麦1175茎秆抗倒伏机制的转录组测序分析

为明确抗倒伏小麦品种黔麦1175茎秆形成的关键因素,在扬花期和成熟期分别测定黔麦1175及易倒伏对照品种黔麦18的生长特性、茎秆特性、纤维素和木质素的含量等性状指标,利用转录组测序技术挖掘调控两个品种茎秆形成的差异表达基因,并对其进行GO功能注释和KEGG富集分析。结果表明,在扬花期,黔麦1175的株高、茎秆重心高度和穗长均显著低于黔麦18,但两品种间的穗重以及茎秆、基部1～2节间的长度和干重均无显著差异;在成熟期,黔麦1175的穗长以及茎秆长度、干重和鲜重均显著低于黔麦18,但穗重、基部1～2节间的长度和干重均无显著差异。黔麦1175的茎秆抗折力、纤维素和木质素的含量均显著高于黔麦18。转录组测序结果表明,各样品的有效数据(clean data)均达到13.85 Gb以上,Q30碱基百分比在93.8%以上。对差异表达基因进行GO功能分类,发现差异表达基因主要涉及催化活性、结合、代谢过程、细胞部分、膜部分、细胞过程、细胞器膜、刺激应答、生物调控、转运活性、转录调控活性等通路;KEGG富集分析结果显示,苯丙烷生物合成、DNA复制、光合作用-天线蛋白、植物激素信号转导等通路富集到的差异表达...     

Biobleaching of unbleached and oxygen-bleached hardwood kraft pulp by culture filtrate containing manganese peroxidase and lignin peroxidase fromPhanerochaete chrysosporium

Unbleached and oxygen-bleached hardwood kraft pulp (UKP and OKP), respectively, were bleached with a culture filtrate containing manganese peroxidase (MnP) and lignin peroxidase (LiP) fromPhanerochaete chrysosporium Burds. The brightness increases of UKP upon biobleaching with the culture filtrate with and without MnSO₄ were the same. The brightness increase of OKP with MnSO₄ decreased to about half that seen without MnSO₄. Changes in the brightness of UKP and OKP by treatment with the culture filtrate were determined. The brightness increased sharply by about eight points during the first 3h. The 3-h treatment was repeated seven times. The brightness increased linearly with the bleaching of UKP. On bleaching of OKP, the brightness increased slowly and stopped at about 78%.Part of this report was presented at the 62nd Pulp and Paper Research Conference of the Japan Tappi, Tokyo, June 1995     

食用菌对山杨木质素及纤维素的降解

选择了10个对杨树木质素和纤维素有降解能力的菌种:榆黄蘑、香菇、金针菇、木耳、裂褶菌、平菇、茶树菇、杏鲍菇、柳蘑、蟹味菇,测定了能在培养基2上生长的9个菌株的降解木质素和纤维素快慢的先后顺序。用9种食用真菌(除蟹味菇外)对木材的木质素和纤维素降解一定时期后,测定了木质素和纤维素质量分数的变化数据,研究了它们对山杨木材木质素的分解能力。结果得出:裂褶菌先降解纤维素,其余的8种菌株均先降解木质素;降解的快慢与降解率无关;香菇、平菇对山杨的木质素降解率和纤维素降解率均比较高,为降解山杨木质素和纤维素的最佳菌株。     

Increasing maturity reduces wound response and lignification processes against Penicillium expansum (pathogen) and Penicillium digitatum (non-host pathogen) infection in apples

Penicillium expansum is the main postharvest pathogen of pome fruit and is a necrotrophic fungus that requires wounds to infect the fruit. Therefore, injuries caused during harvest and postharvest handling provide an optimal locus for infection. In this study, the effect of wound response in apples harvested at three different maturity stages and stored at two different temperatures (20 and 0 °C) infected with P. expansum (pathogen) and Penicillium digitatum (non-host pathogen) was evaluated. The effect of wounding and pathogen inoculation on lignin content was also quantified. At 20 °C, less decay incidence and severity were observed when time between wounding and inoculation increased, and these differences were more important in fruit from immature and commercial harvests. However, at 0 °C, wound response was too slow to prevent P. expansum infection. Lignin content was highest in fruit from the immature harvest. Our results indicated that maturity and storage temperature play an important role in apple wound response. This is the first report demonstrating that P. digitatum, a non-host pathogen, was able to develop rots in over-mature apples.     

木质素与蚯蚓对黑麦草生物量及土壤微生物群落的影响

采集农田土壤,设置添加木质素和蚯蚓不同组合处理的黑麦草盆栽试验,在测定植物生物量的基础上,结合定量PCR、高通量测序等方法,研究木质素和蚯蚓及其联合作用对土壤细菌、真菌群落的影响。结果显示:木质素显著降低了黑麦草的生物量,而蚯蚓能够缓解木质素的抑制作用,促进黑麦草生长。木质素明显抑制了土壤细菌、真菌数量,并改变群落结构,以Sphingomonadaceae、Methylophilaceae为标志的降解细菌和担子菌等潜在降解真菌显著富集;单一加入蚯蚓对土壤微生物的影响相对较小,木质素和蚯蚓组合处理显著提高细菌、真菌数量,改变上述降解微生物的丰度。这些结果表明,木质素降低土壤微生物数量,并可能通过其自身降解释放的酚类化感物质抑制植物生长,对土壤生态系统健康产生不利影响;蚯蚓与木质素联合处理影响土壤中木质素降解微生物组成,微生物数量与植物生物量均表现增加趋势,蚯蚓有利于土壤中木质素的微生物代谢,并为植物生长提供更多的养分。本研究为农田生态系统木质素资源化利用提供了科学依据。