云南甘蔗细茎野生种82-114测交后代主要性状遗传分析

利用云南甘蔗细茎野生种82-114(简称:云割82-114)为父本,与甘蔗栽培原种、生产品种和含野生血缘F1等3类亲本进行测交.对后代锤度、茎径、株高、有效茎、蔗产量等5个主要数量性状进行方差、遗传力和配合力分析,结果表明:①组合后代锤度、茎径、株高、有效茎4个性状差异极显著;②组合后代锤度、茎径、株高、有效茎的遗传力表现较突出,均超89.0%;③3类组合中,栽培原种×云割82.114后代有效茎配合力表现明显的正效应,生产品种×云割82-114后代锤度、茎径、株高、蔗产量配合力有比较明显的正效应,舍野生血缘F1×云割82-114后代锤度、茎径、株高、有效茎、蔗产量等5个指标的配合力效应取向不明显.     

甘蔗属不同种及优良甘蔗栽培品种的SSR标记遗传多样性分析

应用21对SSR引物与毛细管电泳技术,分析了52个甘蔗属品种的遗传多样性。共检测出327个SSR标记,平均每对引物检测15.6个。选择141个共显性标记构建SSR标记指纹图谱数据库,利用DNAMAN软件与UPGMA统计方法分析参试材料遗传多样性。DNAMAN软件同源分析显示,新台糖16号与台优1号之间的同源性最高(87%),品种之间最小的同源性为55%;利用UPGMA统计方法可把参试材料分成4个遗传相似性较高的类群。结果表明,SSR标记与毛细管技术的结合,可构建甘蔗种质资源SSR标记指纹图谱、分析甘蔗种质资源遗传多样性。聚类分析显示参试甘蔗材料的遗传基础相近,为了提高甘蔗选育种效率,应拓宽甘蔗选育种亲本的遗传基础,提高杂交栽培品种的抗虫、抗病等特性。     

Asexual endophytes and associated alkaloids alter arthropod community structure and increase herbivore abundances on a native grass

Despite their minute biomass, microbial symbionts of plants potentially alter herbivory, diversity and community structure. Infection of grasses by asexual endophytic fungi often decreases herbivore loads and alters arthropod diversity. However, most studies to date have involved agronomic grasses and often consider only infection status (infected vs. uninfected), without explicitly measuring endophyte-produced alkaloids, which vary among endophyte isolates and may impact consumers. We combined field experiments and population surveys to investigate how endophyte infection and associated alkaloids influence abundances, species richness, evenness and guild structure of arthropod communities on a native grass, Achnatherum robustum (sleepygrass). Surprisingly, we found that endophyte-produced alkaloids were associated with increased herbivore abundances and species richness. Our results suggest that, unlike what has been found in agronomic grass systems, high alkaloid levels in native grasses may not protect host grasses from arthropod herbivores, and may instead more negatively affect natural enemies of herbivores.
Ecology Letters (2010) 13: 106–117     

甘蔗-滇蔗茅杂交F_1花粉母细胞减数分裂过程GISH分析

研究甘蔗属与滇蔗茅属间远缘杂交F1染色体遗传行为具有重要科学意义,可为发掘利用滇蔗茅野生优异基因资源提供细胞学依据。本研究采用常规压片技术对可育父本及不育杂交F1花粉母细胞减数分裂过程进行比较观察,结果显示可育父本云南95-19减数分裂正常,而不育杂交F1分裂异常;进一步对F1花粉母细胞减数分裂过程进行基因组荧光原位杂交(GISH,genome in situ hybridization)分析,结果表明:滇蔗茅与甘蔗属热带种的亲缘关系较远,双亲染色体在F1细胞中不能进行同源配对,终变期,15条滇蔗茅染色体以单价体形式存在,花粉母细胞减数分裂细胞中存在滞后染色体、染色体丢失和不均衡分离现象。甘蔗-滇蔗茅属间远缘杂交F1花粉母细胞减数分裂异常因而杂交F1花粉完全败育。     

Contribution of N from green harvest residues for sugarcane nutrition in Brazil

Brazil is recognized as a prominent renewable energy producer due to the production of ethanol from sugarcane. However, in order for this source of energy to be considered truly sustainable, conservation management practices, such as harvesting the cane green (without burning) and retaining the trash in the field, need to be adopted. This management practice affects mostly the nitrogen (N) cycle through the effect of trash on immobilization–mineralization of N by soil microorganisms. The aim of the experiments reported here was to evaluate N recovery from trash (trash‐N) by sugarcane during three ratoon crop seasons: 2007, 2008 and 2009. Two field experiments were carried out, one in Jaboticabal and the other in Pradopolis, in the state of Sao Paulo, Brazil. The experiments were set up in a randomized block design with four replications. Within each plot, microplots were installed where the original trash was replaced by trash labelled with ¹⁵N, and maintained up to the fourth crop cycle. Trash‐N recovery was higher in the Jaboticabal site, the most productive one, than in the Pradópolis site. The average trash‐N recovery across the two sites after three crop cycles was 7.6 kg ha^?1 (or 16.2% of the initial N content in trash), with the remaining trash‐N being incorporated into soil organic matter reserves. While these results indicate that the value of trash for sugarcane nutrition is limited in the short term, maintaining trash on the field will serve as a long‐term source of N and C for the soil.     

Genetic diversity and population structure of Sorghum mosaic virus infecting Saccharum spp. hybrids

Sugarcane mosaic disease is widespread in many countries and has been identified to be caused by Sugarcane mosaic virus (SCMV), Sorghum mosaic virus (SrMV) and Sugarcane streak mosaic virus (SCSMV). Viral surveys of SCMV, SrMV and SCSMV were performed from 104 leaf samples of Saccharum spp. hybrid growing in China and two leaf samples in Myanmar. Sorghum mosaic virus was a major causal agent for sugarcane mosaic disease in China whereby 72.1% (75/104) of samples had SrMV infection alone, 6.7% (7/104) were mixed with SCMV and 17.3% (18/104) were mixed with SCSMV. Sugarcane streak mosaic virus infection alone occurred in 3.8% (4/104) of samples, but no single infections were observed for SCMV. Two viruses (SrMV and SCSMV) were detected in sugarcane mosaic samples in Myanmar. Phylogenetic analysis revealed that all of the SrMV isolates were clustered into three major lineages encompassing six phylogroups/genotypes based on the CP sequences (825 nucleotides) of 113 Chinese and 2 Burmese isolates from this study and 73 isolates reported worldwide. Six clearly distinct SrMV phylogroups (G1–G6) were formed and shared 74.3–94.1% nucleotide identity and 84.7–98.1% amino acid identity of CP sequences. SrMV‐G5 was identified to be new distinct phylogroup that was restricted to the Fujian and Guangxi provinces. The unique SrMV‐G6 phylogroup only occurred in Yunnan province. Insertion/deletion mutations, negative selection and frequent gene flow are factors driving the genetic evolution and population structure of SrMV in China.     

Can chilling tolerance of C4 photosynthesis in Miscanthus be transferred to sugarcane?

The goal of this study was to investigate whether chilling tolerance of C₄ photosynthesis in Miscanthus can be transferred to sugarcane by hybridization. Net leaf CO₂ uptake (A_sat) and the maximum operating efficiency of photosystem II (Ф_PSII) were measured in warm conditions (25 °C/20 °C), and then during and following a chilling treatment of 10 °C/5 °C for 11 day in controlled environment chambers. Two of three hybrids (miscanes), ‘US 84‐1058’ and ‘US 87‐1019’, did not differ significantly from the chilling tolerant M. ×giganteus ‘Illinois’ (Mxg), for A_sat, and Φ_PSII measured during chilling. For Mxg grown at 10 °C/5 °C for 11 days, A_sat was 4.4 μmol m^?2 s^?1, while for miscane ‘US 84‐1058’ and ‘US 87‐1019’, A_sat was 5.7 and 3.5 μmol m^?2 s^?1, respectively. Miscanes ‘US 84‐1058’ and ‘US 87‐1019’ and Mxg had significantly higher rates of A_sat during chilling than three tested sugarcanes. A third miscane showed lower rates than Mxg during chilling, but recovered to higher rates than sugarcane upon return to warm conditions. Chilling tolerance of ‘US 84‐1058’ was further confirmed under autumn field conditions in southern Illinois. The selected chilling tolerant miscanes have particular value for biomass feedstock and biofuel production and at the same time they can be a starting point for extending sugarcane's range to colder climates.     

甘蔗节间蔗糖含量与和蔗糖代谢相关的4种酶活性之间的关系剖析

测定和分析2个品种甘蔗节间蔗糖含量与和蔗糖代谢相关的4种酶活性之间关系的结果表明:节间蔗糖含量与酸性转化酶活性成极显著负相关,与蔗糖磷酸合成酶活性呈显著正相关。从通径分析结果可知,4种关键酶中可溶性酸性转化酶和蔗糖磷酸合成酶是对蔗糖含量贡献程度最大的2个酶.     

Antiproliferative and antioxidant activities of a tricin acylated glycoside from sugarcane (Saccharum officinarum) juice

From sugarcane juice, a flavone, identified by spectroscopic methods as tricin-7-O-β-(6″-methoxycinnamic)-glucoside, was isolated, in addition to orientin. The tricin derivative was shown to have antioxidant activity higher than Trolox^® by means of the DPPH assay and lower by the β-carotene/linoleic acid system. It showed in vitro antiproliferative activity against several human cancer cell lines, with higher selectivity toward cells of the breast resistant NIC/ADR line.     

Production of polyhydroxybutyrate in sugarcane

We report here the production of the bacterial polyester, polyhydroxybutyrate (PHB), in the crop species sugarcane ( Saccharum spp. hybrids). The PHB biosynthesis enzymes of Ralstonia eutropha [β-ketothiolase (PHAA), acetoacetyl-reductase (PHAB) and PHB synthase (PHAC)] were expressed in the cytosol or targeted to mitochondria or plastids. PHB accumulated in cytosolic lines at trace amounts, but was not detected in mitochondrial lines. In plastidic lines, PHB accumulated in leaves to a maximum of 1.88% of dry weight without obvious deleterious effects. Epifluorescence and electron microscopy of leaf sections from these lines revealed that PHB granules were visible in plastids of most cell types, except mesophyll cells. The concentration of PHB in culm internodes of plastidic lines was substantially lower than in leaves. Western blot analysis of these lines indicated that expression of the PHB biosynthesis proteins was not limiting in culm internodes. Epifluorescence microscopy of culm internode sections from plastidic lines showed that PHB granules were visible in most cell types, except photosynthetic cortical cells in the rind, and that the lower PHB concentration in culm internodes was probably a result of dilution of PHB-containing cells by the large number of cells with little or no PHB. We discuss strategies for producing PHB in mitochondria and mesophyll cell plastids, and for increasing PHB yields in culms.