Sorghum, an African grass related to sugar cane and maize, is grown for food, feed, fibre and fuel. We present an initial analysis of the approximately 730-megabase Sorghum bicolor (L.) Moench genome, placing approximately 98% of genes in their chromosomal context using whole-genome shotgun sequence validated by genetic, physical and syntenic information. Genetic recombination is largely confined to about one-third of the sorghum genome with gene order and density similar to those of rice. Retrotransposon accumulation in recombinationally recalcitrant heterochromatin explains the approximately 75% larger genome size of sorghum compared with rice. Although gene and repetitive DNA distributions have been preserved since palaeopolyploidization approximately 70 million years ago, most duplicated gene sets lost one member before the sorghum-rice divergence. Concerted evolution makes one duplicated chromosomal segment appear to be only a few million years old. About 24% of genes are grass-specific and 7% are sorghum-specific. Recent gene and microRNA duplications may contribute to sorghum's drought tolerance.

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The Sorghum bicolor genome and the diversification of grasses

羟氨苄青霉素引起大疱性类天疱疮样疹

The Report, Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply (generally referred to as the Billion-Ton Study or 2005 BTS), was an estimate of “potential” biomass within the contiguous United States based on numerous assumptions about current and
future inventory and production capacity, availability, and technology. In the 2005 BTS, a strategic analysis was undertaken to determine if U.S. agriculture and forest resources have the capability to potentially produce at least one billion dry tons of biomass annually, in a sustainable manner—enough to displace approximately
30% of the country’s present petroleum consumption. To ensure reasonable confidence in the study results, an effort was made to use relatively conservative assumptions. However, for both agriculture and forestry, the resource potential was not restricted by price. That is, all identified biomass was potentially available, even though some potential feedstock would more than likely be too expensive to actually be economically available.
In addition to updating the 2005 study, this report attempts to address a number of its shortcomings

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U.S. Billion-ton Update: Biomass Supply for a Bioenergy and Bioproducts Industry

Heritability (H) on a progeny mean basis is frequently estimated in recurrent selection experiments for the purpose of estimating the expected progress from family selection; however, appropriate measures of precision have been developed for only a few heritability estimators. The objective of this research was to develop a measure of precision for H for certain balanced linear models. Exact confidence intervals for H were derived and are not restricted to a specific experimental design. The confidence intervals were applied to sorghum [Sorghum bicolor (L.) Moench] half-sib family data.

An exact confidence interval for heritability on a progeny mean basis

Data analysis methods.

De nombreux changements ont eu lieu en pathologie de la canne a sucre au cours des dix dernieres annees De nouvelles connaissances sont apparues sur des maladies connues, de nouvelles maladies ont ete decrites et identifiees et, grâce aux progres de la biologie moleculaire, de nouvelles techniques de diagnostic ont ete mises au point C'est pourquoi la section pathologie de la Societe internationale des technologues de la canne a sucre (ISSCT) a decide de publier un nouveau livre sur les maladies de la canne a sucre Son objectif est de fournir une information actualisee relative aux connaissances scientifiques et aux aspects pratiques de la lutte, sans pour autant decrire de facon exhaustive les maladies Chaque maladie fait l'objet d'un chapitre illustre de nombreuses photographies en couleurs, dans lequel sont rassemblees des donnees sur son agent causal, sa distribution geographique, ses symptomes, sa transmission, son spectre d'hotes, son epidemiologie et son importance economique Des informations concernant les souches de l'agent pathogene, le diagnostic et la lutte ainsi qu'une bibliographie completent chacun de ces chapitres (Resume d'auteur)

A guide to sugarcane diseases.

Sugarcane improvement through breeding and biotechnology

Incidence of yellow leaf syndrome in CP cultivars based on polymerase chain reaction and serological techniques

Problem statement: Approximately 20% of sugarcane (Saccharum spp.) is grown on sand soils in south Florida, USA. Sugarcane yields in the region linearly increased in last 33 years on organic (muck) soils, but not on sand soils. Water deficit during the formative growth phase on sand soils probably limits sugarcane yields. Approach: A greenhouse study was conducted in 2009 and 2010 to evaluate the physiological and growth responses of sugarcane to water-deficit stress during formative growth. Treatments included organic (muck) and sand soils and two water regimes Well Watered (WW) and Water-Deficit Stress (WS). Sugarcane cultivar CP 80-1743 was planted in pots and fertilized with N, P and K based on soil analyses. All pots were well watered until 58 days after planting, when water was withheld from the WS pots. During the WS treatment, plant growth rate, leaf Relative Water Content (RWC), proline content and photosynthesis components were measured. Final tillers, Green Leaf Area (GLA) and shoot biomass were determined 27 (in 2009) or 22 (in 2010) days after initiating the WS treatment. Results: Stress symptoms of sugarcane plants appeared 7-10 days earlier on sand soil than on muck soil. Water stress reduced stomatal conductance (gs), Photosystem II Photochemical Efficiency (ΦPSII), leaf Photosynthesis rate (Pn), the number of tillers and GLA, resulting in reduced shoot biomass, especially on sand soil. Neither leaf RWC nor proline content was a sensitive WS indicator. Conclusion: Nondestructive measurements of physiological traits of gs, ΦPSII and Pn during the formative stage may be useful for early detection of water stress in sugarcane.

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Sugarcane Response to Water-Deficit Stress during Early Growth on Organic and Sand Soils

Orange rust of sugarcane (Saccharum spp. hybrids), caused by Puccinia kuehnii, is a relatively new disease in the Western Hemisphere that substantially reduces yields in susceptible sugarcane genotypes. The objective of this study was to determine the physiological mechanisms of orange rust-induced reductions in sugarcane growth and yield by quantifying effects of the disease on leaf SPAD index (an indication of leaf chlorophyll content), net photosynthetic rate, dark respiration, maximum quantum yield of CO2 assimilation, carbon fixation efficiency, and the relationships between these leaf photosynthetic components and rust disease ratings. Plants growing in pots were inoculated with the orange rust pathogen using a leaf whorl inoculation method. A disease rating was assigned using a scale from 0 to 4 with intervals of 0.5. At disease ratings ≥2, the rust-infected leaf portion of inoculated plants showed significant reductions in SPAD index, maximum quantum yield, carbon fixation efficiency, stomatal conductance, leaf transpiration rate, and net photosynthetic rate; but the rusted portion of the infected leaves had increased intercellular CO2 concentration and leaf dark respiration rate. Although leaf SPAD index, photosynthetic rate, stomatal conductance, and transpiration rate at the rust-infected portion decreased linearly with increased rust rating, the effect of orange rust on photosynthetic rate was much greater than that on stomatal conductance and transpiration. Unlike earlier reports on other crops, reduction in leaf photosynthesis by orange rust under low light was greater than that under high light conditions. These results help improve the understanding of orange rust etiology and physiological bases of sugarcane yield loss caused by orange rust.

https://apsjournals.apsnet.org/doi/pdf/10.1094/PDIS-10-10-0762

Jack C. Comstock

Papers

A guide to sugarcane diseases.

Sugarcane improvement through breeding and biotechnology

Incidence of yellow leaf syndrome in CP cultivars based on polymerase chain reaction and serological techniques

Sugarcane Response to Water-Deficit Stress during Early Growth on Organic and Sand Soils

Orange Rust Effects on Leaf Photosynthesis and Related Characters of Sugarcane