木薯种质花期观察和亲和力的初步研究

主要概述了我国木薯种质的开花习性，同时对不同时段授粉的稔实率，不同种质作为亲本的稔实率进行了统计分析。     

木薯干旱胁迫响应基因MeGSTU7自然变异分析

在2个木薯品种中检测MeGSTU7基因在不同干旱胁迫阶段的表达量变化，并克隆测序了60个木薯品种的基因区DNA序列，分析基因核苷酸多态性及其自然变异，并将核苷酸多态性与干旱胁迫表型关联分析，挖掘优等位变异。结果表明，干旱胁迫条件下，2个品种的MeGSTU7的表达量均上调。MeGSTU7基因区核苷酸变异丰富，共有23个SNP位点，A/G突变为主；外显子区总计10个同义突变，12个非同义突变；外显子区在品种资源群体中有4种主要单倍型，所有的单倍型分为两大类，分子进化分析表明，MeGSTU7的外显子区的两端受到很强的正选择作用；Q+K+MLM混合线性模型关联分析结果表明，1个Indel和2个SNP与干旱胁迫下地上部鲜重耐旱系数显著关联，并筛选得到了优等位变异。     

木薯细菌性萎蔫病菌抗铜性评价及抗铜相关基因簇分子分析

细菌性萎蔫病是世界范围内木薯种植中的重要病害,也是中国木薯种植中为害最严重的病害。前期研究发现铜基杀菌剂对国内木薯细菌性萎蔫病防效欠佳,随即开展了病菌抗铜性评价及抗铜相关基因簇的分子分析工作。评价了42个不同来源病原菌菌株对硫酸铜的抗性,发现其抑菌最低有效浓度均在1.35~1.75 mmol/L之间。通过和已报道黄单胞菌类抗铜相关基因的比对分析,发现来自广西的菌株GX11携带有cop TAB和Xme RSA2个抗铜基因簇。对来自南美州、非洲和亚洲67个菌株的基因组序列分析发现绝大多数菌株均带有这2个基因簇,聚类分析发现相关基因在菌株之间具高度的同源性。     

Effects of Three Strains Combinations of Lactobasillus buchneri,Aspergillus niger,Candida tropicalis,Bacillus subtilis and Lactobacillus plantarum on Fermentation Quality of Cassava Residue

The experiment was carried out to investigate effects of three strains combinations of Lactobasillus buchneri (LAB),Aspergillus niger (AN),Candida tropicalis (CT),Bacillus subtilis (BS) and Lactobacillus plantarum (LAP) on fermentation quality of cassava residue.In this study,cassava residue were used as fermentative raw material,three strains were combined by 1∶1∶1 chosen from LAB,AN,CT,BS and LAP,getting five different combination.Combination 1:LAB+AN+LAP;Combination 2:LAB+CT+LAP;Combination 3:LAB+BS+LAP;Combination 4:AN+CT+LAP;Combination 5:CT+BS+LAP;1% urea or 1% urea+0.6% brown sugar was added to each combination;Blank group was without any additives;1% urea was added to control group Ⅰ and 1% urea+0.6% brown sugar were added to control groupⅡ.Experimental group Ⅰ was consisted of control group Ⅰ+different combination (1-5) while experimental group Ⅱ was consisted of control group Ⅱ+different combination (1-5).Water content in each group was about 65% by modulating with normal saline,each group was fermented in the vacuum of polyethylene film bag for 10 days.The results showed as follows:①pH of each experimental group was significantly lower than that of blank group and control group (P < 0.05),experimental group Ⅱ1 (LAB+AN+LAP+urea+brown sugar) could improve acetic acid content of cassava residue and reduce the NDF and ADF contents,and which were the lowest and were significantly lower than that of blank group and the control groups (P < 0.05);②Experimental group Ⅱ5 (CT+BS+LAP+urea+brown sugar) could improve the crude protein content in the cassava residue which was significantly higher than that of blank group and the control groups (P < 0.05);③It was favorable to propionic acid production by adding the corresponding strains+urea+brown sugar to the cassava residue fermentation;④Urea and brown sugar were added into cassava residue for improving the nutrition composition during the fermentation process was better than that only urea was added;⑤When the urea was added into the fermentation medium,the crude protein content in cassava residue was significantly increased,when cassava residue fermented quality was evaluate by butyric acid and acetic acid contents,all the groups got to the top of grade.In conclusion,solid-state fermentation using LAB+AN+LAP+urea+brown sugar or CT+BS+LAP+urea+brown sugar could offer an effective alternative to improve the fermentation quality of cassava residue.     

保鲜剂联合热处理对木薯品质及贮藏效果的影响

以华南9号木薯为试验材料,采用不同保鲜剂浸泡经热处理(60℃,5 min)后的木薯,通过测定其贮藏过程中的理化、生化指标来评价不同处理方式对木薯品质及保鲜效果的影响。结果表明:与对照相比,保鲜剂C(1.5%壳聚糖+0.15%柠檬酸+0.25%氯化钙)可显著延缓木薯块根硬度的下降,抑制色泽(L*)值的上升,延缓淀粉的降解和可溶性固形物(TSS)的增加,维持了较高水平的超氧化物歧化酶(Superoxide dismutase,SOD)活性,延缓过氧化物酶(Peroxidase,POD)活性的增加,降低了总酚含量,有效地延长了采后木薯块根的贮藏期,抑制了其品质的劣变。     

木薯杆粉碎还田机的研制

针对木薯收获的需要,研究开发一款木薯茎杆(以下统称木薯杆)粉碎还田机械。根据木薯杆砍伐、收集、粉碎作业的特点,该机器采用拖拉机前悬挂布置方式,由液压系统传递动力,集合木薯杆砍伐、收集、粉碎功能,是木薯全程机械化种植的重要组成部分。