Evaluation of Sweet Sorghum and Sorghum × Sudangrass Hybrids as Feedstocks for Ethanol Production

Field studies were conducted at the USDA-ARS Sugarcane Research Laboratory in southeast Louisiana to evaluate the ethanol yield potential of five sweet sorghums (Dale, M81-E, Rio, Theis, and Topper) and two non-flowering sorghum × sudangrass forage hybrids (MMR 333/27 and MMR 333/47). The sorghums were planted in the spring and harvested at 85, 101, 119, and 138 days after planting (DAP). Theoretical sugar-based ethanol yield increased for the sweet sorghums (except Rio) from 85 through 119 days, but did not significantly increase further at 138 days. The forage sorghums did not show a similar increase, though the theoretical sugar-based ethanol yield of MMR 333/47 at 138 DAP was greater than at 85 DAP. Conversely, theoretical fiber-based ethanol yields increased two-fold in the two forage sorghums from 85 to 138 DAP; a significant increase in fiber-based ethanol yield was not observed in any of the sweet sorghums over the same period. At 138 DAP, sugar-based ethanol yield of Theis (6,060 L ha^?1), was greater than that of Rio or either of the two forage hybrids. Fiber-based ethanol yield of MMR 333/47 (8,860 L ha^?1) was greater than that of any other variety in the test. Theoretical ethanol yield from hexose sugar and fiber components averaged across varieties was 6,500, 7,720, 9,100, and 10,810 L ha^?1 at 85, 101, 119 and 138 DAP, respectively. As a complementary crop for Louisiana’s sugarcane growers, sorghum would need to be harvested not later than 120 DAP so as to not interfere with the planting of sugarcane in these fields. Both Theis and MMR 333/47 produced greater than 11,000 L ha^?1 combined theoretical ethanol at 119 DAP, Theis, equally from sugar and fiber, MMR 333/47 about two-thirds from fiber. Choice of sorghum type would depend on the conversion process(s) being used at the biorefinery.     

Effects of Phosphorus Nutrient on the Hydraulic Conductivity of Sorghum （Sorghum vulgare Pers.） Seedling Roots Under Water Deficiency

Hydroponic experiments were conducted in a growth chamber and changes in the hydraulic conductivity of sorghum (Sorghum vulgare Pers.) roots (Lpr) at the three-leaf stage were measured using the pressure chamber method. Water deficiency was imposed with polyethylene glycol (PEG) 6000 and the phosphorus (P) levels were controlled by complete Hoagland solution with and without P nutrient. The objective of this study was to investigate the effect of P nutrition on root Lpr under water deficiency. The results showed that the Lpr in P deficiency treatments decreased markedly, but the Lpr recovered to the same value as that of control when sufficient P was supplied for 4-24 h. Water deficiency decreased Lpr, but the hydraulic conductivity of the roots with sufficient P supply was still higher than that of plants without P supply. When resuming water supply, the Lpr of the water-deficient plants under P supply recovered faster than that of plants without P supply, which indicates that plants with sufficient P nutrient are more drought tolerant and have a greater ability to recover after drought. The treatment of HgCl2 indicated that P nutrient could regulate the Lpr by affecting the activity and the expression levels of aquaporins.     

Sorghum—Its production,utilization and breeding

A corn-like cereal grass which among its 400 known varieties produces broomcorn, the principal material used in the manufacture of brooms, and important edible grains of Africa and Asia—durra, kafir, milo, shallu, kaoliang, feterita and hegari.     

PCR Amplification，Cloning and Sequencing of RbcL Coding Region in Mesophyll Cell and Bundle Sheath Cell of Sorghum（Sorghum bicolor L．）

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On the Fertilization of Oryza sativa L. × Sorghum vulgare Pets.

1.The pollen germination of Sorghum vulgate appeared normal on the stigma of the Oryza sativa, but the pollen tubes grew slowly in the style. Some of the pollen tubes may become enlarged in their tips or sometimes bursting, while others have continued to grow and entered the embryo sacs. 2. The growth rate of the pollen tubes varied widely. A few pollen tubes were observed in the embryo sacs of the materials 2 hours after pollination, but most of them entered the embryo sacs much later. 3. The zygote associated with a paucity of endosperm nuclei was observed in the materials 1 day after pollination. The double fertilization and 8–12-celled proembryo associated with a number of the free nuclei of the endosperm appeared with a rather high frequency (10.3%) in the materials 3 days after pollination. Some of them are normal in appearance and others may show more or less abnormalities. 4. No division figure was found except in one single case in which mitoses have occurred in both the proembryo and the endosperm. It is most likely that in such case the proembryo and the endosperm if left intact might develop further. 5. A 80-celled embryo was the biggest one which appeared in the materials 5 days after pollination. In general, no cells were ever formed in the endosperm, except in one instance among the 7 days materials the endosperm became cellular in micropylar end. In all other cases the endosperm either ceased to develop early or disorganized. The disorganized endosperm materials are considered to be utilized by the embryo. 6. In certain instances the free nuclei of the endosperm were not distributed at random. They were not equal in size and might fuse into giant nuclelei. 7. The most striking feature is that in the embryo sacs, in which double fertilization or proembryo and endosperm have occurred, a dark stained pollen tube was commonly present. This fact leads us to the conviction that in general only if a healthy pollen tube entered the embryo sac, double fertilization can take place and further development can proceed. 8. In certain cases the protoplasm of the embryo cells appeared scanty. It is apparently that the normal metabolism of the embryo was disturbed owing to the lack of nutrient, and the death of the embryo ensued. 9. No differentiated embryo was observed and no mature seeds were produced. The materials fixed 12 days after pollination showed a variety of abnormalities and collapses. The authors believe that the failure of seed production of rice X kaoliang was primarily due to the fact that the pollen tubes in the style grew too slowly to reach the embryo sacs in time. The consequence is that the double fertilization took place only in a late stage while the male and female gametes may have already become unhealthy. In addition, in this late stage the stored starch in the maternal tissues having gradually disappeared, the nutrient supply to the embryo sac was therefore limited and the young embryo and endosperm were finally in starvation.     

The Accumulation of Free Proline and Its Roles in Water-Stressed Sorghum Seedlings

The role of proline has recently been a sub-ject of intensive research. This stems from:(1) the marked accumulation of free prolinein plants undergoing water stress, salinity, lowtemperature, air pollutants, etc. and possibleroles of accumulated proline in plants (Stewart     

Stable transformation of Sorghum bicolor protoplasts with chimeric neomycin phosphotransferase II and β-glucuronidase genes

Summary Parameters influencing the stable transformation of Sorghum bicolor protoplasts with a chimeric neomycin phosphotransferase II (NPT II) gene by electroporation were investigated. The mean number of kanamycin-resistant calli produced increased in direct proportion to the concentration of DNA used for transformation. Linearization of the plasmid doubled the mean number of kanamycin-resistant calli produced, while the addition of carrier DNA had no effect. The copy number (1–4) of integrated genes was low compared with that frequently reported for PEG-mediated transformation. Two strategies for transforming protoplasts with a nonselectable, -glucuronidase (GUS) gene were compared. One utilized a plasmid containing a CaMV 35S-NPT II gene covalently linked to a CaMV 35S-GUS gene, and the other strategy utilized the two genes on separate plasmids. DNA from all 77 kanamycin-resistant calli analyzed contained restriction fragments hybridizing to the NPT II probe; approximately 70% of the clones from all transformation treatments contained a 1.7-kb EcoRI/HindIII restriction fragment corresponding to the full-length gene. Of the kanamycin-resistant calli, 38–63% (depending on the transformation treatment) contained GUS-hybridizing fragments, and 8–19% contained the full-length gene. The addition of NPT II and GUS genes on a single plasmid or on separate plasmids did not appear to lead to an appreciable difference in the frequency of cointegration of these genes, although an increased proportion of the plasmid bearing the nonselectable (GUS) gene appeared to favor its cointegration.     

Cloning and Sequencing of the cDNA Fragment Containing Sorghum Actin Gene（SoAcl）

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Perturbed reproductive development in salt-treated Sorghum bicolor: a consequence of modifications in regulation networks?

In Sorghum bicolor, tolerance to salinity is improved by a 3-week treatment with 150 mM NaCl during early vegetative development. However, a strong decrease in fertility is also observed, suggesting that reproductive development becomes perturbed by this adaptive response to salinity. This study is an attempt to clarify the origin of such a paradoxical phenomenon. The relationships between end-cycle characters are modified by the NaCl treatment: some linkages disappear, while others are strengthened, especially those linking fertility with plant height. In parallel, a transient reduced level of linkage between leaf characters is observed around the unfolding of the eighth to the tenth leaves, defining a critical period in vegetative development separating two discrete phases. A relationship is observed between events occurring during this short critical period and the NaCl-induced perturbations in fertility. This suggests that reproductive development is conditioned by the influence of salinity on events occurring during a short period of vegetative development, independently of the level of tolerance to salinity quantified by the rate of vegetative growth.     

Agricultural Biodiversity in Northwest Somalia – an Assessment Among Selected Somali Sorghum(<Emphasis Type="Italic">Sorghum bicolor</Emphasis> (L.) Moench) Germplasm

The seed sector situation in Northwest Somalia is critical. The availability of food has decreased and many people are at risk of hunger. Food security can be restored by enhancing the local genetic resources and creating an efficient seed sector. Sorghum is important as a food and fodder crop in this region. It is close to Ethiopia, which is considered as the probable origin and domestication of Sorghum. Twelve morphological and productive characteristics were chosen to assess the phenotypic variability of 16 accessions of sorghum from Northwest Somalia. Univariate (analysis of variance and G test) and multivariate (discriminant and cluster analysis) methods were used to assess the morphological variation within the accession and to group the 16 accessions into clusters based upon quantitative and qualitative characters. Elmi Jama Cas, Masego Cas, Masego Cad and Carabi clearly represent distinct landraces with specific features suitable for different purpose, such as grain and/or forage production. Each landrace tested is able to grow under harsh environmental conditions, thus ensuring a low, but stable production for small poor resources farmers. Knowledge and conservation of local landraces will provide a broad base of genetic variability from which improved sorghum varieties can be developed, thus aiding in the stabilisation of a secure and sustainable food supply for farmers of Northwest Somalia.     

高粱苗(Sorghum vulgare)水分亏缺时所累积的游离脯氨酸的来源

在完全营养液中,用Glu或Ala替代Ca(NO_3)_2为氮源时,在水分胁迫条件下可得到同样程度的Pro累积量。但是用Ser为氮源时,在正常水分条件下Glu和Ala的相对含量较少,Ser和Gln相对含量较高,在水分胁迫条件下,Pro的累积受到抑制。在缺钾营养液中培养时,植株游离氨基酸中Glu和Ala相对量较少,Ser和Gln相对量较高,在水分胁迫条件下,Pro累积也受到抑制。在缺钾营养液中,用Glu或Ala替代Ca(NO_3)_2为氮源时,在水分胁迫条件下Pro的累积可达到甚至超过完全营养液中Pro的相对量。     

Partial Purification and N-Terminal Amino Acid Sequencing of a β-1,3-Glucanase from Sorghum Leaves

A protein with an apparent molecular mass of 30 kDa that cross-reacts with barley glucanase antiserum was detected in healthy leaves of sorghum (Sorghum bicolor (L.) Moench). When sorghum leaves were infected with Exserohilum turcicum, the causal agent of leaf blight, the 30-kDa glucanase was substantially induced. The 30-kDa glucanase was partially purified from sorghum leaves using ammonium sulfate fractionation and anion exchange chromatography on DEAE-sephacel. The N-terminal amino acid sequence of the 30-kDa glucanase shows homology to glucanases of maize, barley, bean, soybean, tobacco and pea. The purified 30-kDa glucanase showed antifungal activity against Trichoderma viride.     

Structure and Expression of a Dhurrinase (β-Glucosidase) from Sorghum

Sorghum (Sorghum bicolor L. Moench) has two isozymes of the cyanogenic β-glucosidase dhurrinase: dhurrinase-1 (Dhr1) and dhurrinase-2 (Dhr2). A nearly full-length cDNA encoding dhurrinase was isolated from 4-d-old etiolated seedlings and sequenced. The cDNA has a 1695-nucleotide-long open reading frame, which codes for a 565-amino acid-long precursor and a 514-amino acid-long mature protein, respectively. Deduced amino acid sequence of the sorghum Dhr showed 70% identity with two maize (Zea mays) β-glucosidase isozymes. Southern-blot data suggested that β-glu-cosidase is encoded by a small multigene family in sorghum. Northern-blot data indicated that the mRNA corresponding to the cloned Dhr cDNA is present at high levels in the node and upper half of the mesocotyl in etiolated seedlings but at low levels in the root—only in the zone of elongation and the tip region. Light-grown seedling parts had lower levels of Dhr mRNA than those of etiolated seedlings. Immunoblot analysis performed using maize-anti-β-glucosidase sera detected two distinct dhurrinases (57 and 62 kD) in sorghum. The distribution of Dhr activity in different plant parts supports the mRNA and immunoreactive protein data, suggesting that the cloned cDNA corresponds to the Dhr1 (57 kD) isozyme and that the dhr1 gene shows organ-specific expression.     

Properties of the isoforms of α-amylase from kilned and unkilned malted sorghum (Sorghum bicolor)

We have previously reported the presence of a relatively heat-stable α-amylase with a low K_m for starch in kilned malted sorghum. In order to establish the industrially useful and more efficient isoforms, we have separated this α-amylase into different isoforms using both cation and anion-exchange chromatographies. Unkilned malted α-amylase crude was separated into three different isoforms (a1, a2 and a3) whereas kilned samples were separated into two (a1 and a2). Apparently one isoform (a3) was lost during kilning due to heat lability. a1 isoform which appears to have a neutral pI and constitute about 60% of the total α-amylases protein that were induced during germination, have the lowest K_m for starch. They are more generally stable than other isoforms at all the temperatures studied. These isoforms lost only 10% activity at 80 °C for 30 min and still had some residual activity at 100 °C incubation for 30 min. a1 isoform could therefore be adapted for industrial starch conversion processes which are carried out within this range of gelatinizing temperatures because of its properties.     

晋杂四号高粱(Sorghum vulgare cv.Jinza4)颖片花色素的分析

通过纸色谱法、光谱法、AlCl_3红移和显色试验,从红高粱颖片的乙醇提取液中分离和鉴定出了5、7、4′—三羟花色(钅羊)和5、7、3′、4′—四羟花色(钅羊)两种花色素。从颖片中还分离出了紫棕色、黄色和淡红色的花色素类。     

A high-density genetic map of Sorghum bicolor (L.) Moench based on 2926 AFLP®, RFLP and SSR markers

Using AFLP technology and a recombinant inbred line population derived from the sorghum cross of BTx623 × IS3620C, a high-density genetic map of the sorghum genome was constructed. The 1713 cM map encompassed 2926 loci distributed on ten linkage groups; 2454 of those loci are AFLP products generated from either the EcoRI/MseI or PstI/MseI enzyme combinations. Among the non-AFLP markers, 136 are SSRs previously mapped in sorghum, and 203 are cDNA and genomic clones from rice, barley, oat, and maize. This latter group of markers has been mapped in various grass species and, as such, can serve as reference markers in comparative mapping. Of the nearly 3000 markers mapped, 692 comprised a LOD 3.0 framework map on which the remaining markers were placed with lower resolution (LOD <3.0). By comparing the map positions of the common grass markers in all sorghum maps reported to date, it was determined that these reference markers were essentially collinear in all published maps. Some clustering of the EcoRI/MseI AFLP markers was observed, possibly in centromeric regions. In general, however, the AFLP markers filled most of the gaps left by the RFLP/SSR markers demonstrating that AFLP technology is effective in providing excellent genome coverage. A web site, http://SorghumGenome.tamu.edu, has been created to provide all the necessary information to facilitate the use of this map and the 2590 PCR-based markers. Finally, we discuss how the information contained in this map is being integrated into a sorghum physical map for map-based gene isolation, comparative genome analysis, and as a source of sequence-ready clones for genome sequencing projects.