Introgresi��n del car��cter tama��o de gluma corta y menor cobertura de grano en poblaciones mejoradas y formaci��n de l��neas isog��nicas de sorgo para grano (Sorghum bicolor [L.] Moench).

Tesis (Doctor en Ciencias Agr��colas con Orientaci��n en Mejoramiento de Plantas Forrajeras) UANL, 2009.

Calagem e diagnose foliar em sorgo sacarino (Sorghum bicolor L. moench)

Os efeitos da aplica����o de cinco n��veis de calc��rio dolom��tico (0 - 1,25 - 2,50-5,00 e 10,00 t/ha) foram estudados em um Latossol Vermelho Escuro textura m��dia. A calagem aumentou a produ����o de colmos de sorgo sacarino, sendo que as produ����es mais elevadas foram obtidas quando a soma de c��lcio e magn��sio, satura����o em bases e valor pH do solo eram, respectivamente, 2,93 meq/100 cm��, 59% e 5,71. Foram observados desequil��brios na nutri����o pot��ssica com a aplica����o de 10 t/ha de calc��rio dolom��tico. Os n��veis cr��ticos de Mg nas folhas + 4e + 3, coletadas, respectivamente, aos 45e 83 dias, foram 0,19 e 0,31% A qualidade do caldo n��o foi alterada significativamente pelas doses de calc��rio dolom��tico empregadas.

Caracter��sticas agron��micas e composi����o qu��mica de oito h��bridos de sorgo [Sorghum bicolor (L.) Moench]

O experimento foi conduzido com o objetivo de avaliar as caracter��sticas agron��micas, composi����o qu��mica das fra����es e da planta inteira de oito h��bridos de sorgo, semeados em mar��o de 2000, no sentido de contribuir para os programas de sele����o de germoplamas resistentes aos efeitos das estiagens prolongadas e, ao mesmo tempo, apropriados ao processo de ensilagem. Utilizou-se o delineamento em blocos ao acaso com oito tratamentos e tr��s repeti����es, para avaliar os h��bridos AG-2005, BR-700, MASSA-03, 498111, 65E3, 698005, 698007 e 699005. N��o houve diferen��as significativas entre produ����o de mat��ria seca (PMS) e propor����o de folhas dos h��bridos avaliados. A maior propor����o de colmo (41,3%) foi observada no 498111 e a menor no MASSA-03 (28,9%). O h��brido 65E3 apresentou a maior propor����o de pan��cula (43,2%) e o 498111 a menor (28,9%). Quanto �� composi����o qu��mica da planta inteira, n��o foram observadas diferen��as significativas entre os h��bridos quanto aos teores de mat��ria seca, mat��ria mineral, hemicelulose, nitrog��nio insol��vel em detergente neutro, nitrog��nio insol��vel em detergente ��cido e nutrientes digest��veis totais (NDT). Os teores de prote��na bruta variaram de 6,5 a 8,8%, fibra em detergente neutro de 57,0 a 70,3%, fibra em detergente ��cido de 29,8 a 36,2%, celulose de 25,3 a 31,2% e lignina de 3,6 a 5,5%, sendo estatisticamente diferentes entre os h��bridos. O 699005 apresentou o maior teor de carboidratos sol��veis (14,5%), diferindo estatisticamente apenas do h��brido 698007 (9,6%). Os h��bridos tamb��m mostraram diferen��as na composi����o qu��mica das fra����es folhas, colmo e pan��cula. de forma geral, todos os h��bridos apresentaram teores de mat��ria seca e carboidratos sol��veis adequados ao processo de ensilagem. As produ����es m��dias de mat��ria seca dos h��bridos (6,2 t/ha), foram altas considerando-se a baixa precipita����o ocorrida durante o per��odo experimental. A an��lise de Cluster sugeriu o agrupamento dos h��bridos de maior PMS e menores porcentagens de pan��cula e NDT e h��bridos de menor PMS, por��m com maiores porcentagens de pan��cula e NDT.

Consumo, digestibilidade dos nutrientes e desempenho de bovinos de corte recebendo silagem de sorgo (Sorghum bicolor (L.) Moench) e diferentes propor����es de concentrado

Conselho Nacional de Desenvolvimento Cient��fico e Tecnol��gico (CNPq)

Consumo e digestibilidade de silagem de sorgo (Sorghum bicolor [L.] Moench) como alternativa para alimenta����o suplementar de ruminantes na Amaz��nia Oriental

Este trabalho foi realizado na Embrapa Amaz��nia Oriental, em Bel��m, Par��, (1��28�� S 48��27�� W de Greenwich), para avaliar o efeito de quatro n��veis (0%, 15%, 30% e 45%) de concentrado, com subprodutos da agroind��stria regional, em substitui����o �� silagem de sorgo, no consumo volunt��rio e digestibilidade aparente da mat��ria seca (MS), prote��na bruta (PB), energia bruta (EB), fibra em detergente neutro (FDN) e fibra em detergente ��cido (FDA). Foi realizado um ensaio metab��lico, em 14 dias de adapta����o e sete dias de per��odo experimental, utilizando-se dezesseis ovinos, de cinco meses e m��dia de 23 kg, em delineamento inteiramente casualizado, com quatro tratamentos e quatro repeti����es. Os dados foram analisados pelo software SAS. A inclus��o de concentrado na dieta influenciou o consumo volunt��rio e a digestibilidade aparente de todos os nutrientes, sendo descrito por fun����o quadr��tica. Constatou-se um aumento quadr��tico nos consumos aparentes da MS e MO, contudo, com aumento do n��vel de concentrado na ra����o, foram observadas diminui����es significativas nos teores de FDN e FDA. Percentagens entre 30% e 45% de concentrado na dieta proporcionam melhores consumos e digestibilidades dos nutrientes, exceto de FDN e FDA. A utiliza����o de concentrado na silagem de sorgo, o que proporciona maior disponibilidade de mat��ria seca na forragem e eleva����o do valor nutritivo da ra����o, �� capaz de promover aumento da produtividade animal.

Effects of leaf extracts of Myrcia guianensis (Aubl.) DC. on growth and gene expression during root development of Sorghum bicolor (L.) Moench

The allelopathic potential of leaf extracts from the medicinal plant Myrcia guianensis (Aubl.) DC. was studied in Petri dish bioassays on sorghum and determined the seed germination, germination rate index (GRI), root growth, secondary root number, the genes involved in root development (SHR, PHB, PHV and REV) and microRNA 166 that regulates these genes. The hydroalcoholic extract was more inhibitory than methanol extract (moderate inhibition) and aqueous extract at 25 and 100% concentration were least inhibitory. Application of higher dose of hydroalcoholic M. guianenesis leaf extracts on sorghum seeds, inhibited the root development and changed the expression of SHR and PHB genes and microRNA 166. This suggested that the expression of these genes could be indicator of allelopathic potential for inhibition of root development in sorghum.

Genetic Mapping of Quantitative Trait Loci Associated with Bioenergy Traits, and The Assessment of Genetic Variability in Sweet Sorghum (Sorghum bicolor (L.). Moench)

Sweet sorghum, a botanical variety of sorghum is a potential source of bioenergy because high sugar levels accumulate in its stalks. The objectives of this study were to explore the global diversity of sweet sorghum germplasm, and map the genomic regions that are associated with bioenergy traits. In assessing diversity, 142 sweet sorghum accessions were evaluated with three marker types (SSR, SRAP, and morphological markers) to determine the degree of relatedness among the accessions. The traits measured (anthesis date [AD], plant height [PH], biomass yield [BY], and moisture content [MC]) were all significantly different (P<0.05) among accessions. Morphological marker clustered the accessions into five groups based on PH, MC and AD. The three traits accounted for 92.5% of the variation. There were four and five groups based on SRAP and SSR data respectively classifying accessions mainly on their origin or breeding history. The observed difference between SSR and SRAP based clusters could be attributed to the difference in marker type. SSRs amplify any region of the genome whereas SRAP amplify the open reading frames and promoter regions. Comparing the three marker-type clusters, the markers complimented each other in grouping accessions and would be valuable in assisting breeders to select appropriate lines for crossing. In evaluating QTLs that are associated with bioenergy traits, 165 recombinant inbred lines (RILs) were planted at four environments in Nebraska. A genetic linkage map constructed spanned a length of 1541.3 cM, and generated 18 linkage groups that aligned to the 10 sorghum chromosomes. Fourteen QTLs (6 for brix, 3 for BY, 2 each for AD and MC, and 1 for PH) were mapped. QTLs for the traits that were significantly correlated, colocalized in two clusters on linkage group Sbi01b. Both parents contributed beneficial alleles for most of traits measured, supporting the transgressive segregation in this population. Additional work is needed on exploiting the usefulness of chromosome 1 in breeding sorghum for bioenergy.

An��lisis de una cartera de extensi��n agr��cola para sorgo (Sorghum bicolor L. Moench) en los estados Barinas y Portuguesa, Venezuela.

La presente investigaci��n tuvo como objetivo evaluar el rendimiento y riesgo que presenta la cartera de fincas productoras de sorgo, en los estados Portuguesa y Barinas (Venezuela), adscritas al Programa de Extensi��n Agr��cola Italven S. A. (PEAISA). La muestra fue conformada por 39 fincas localizadas en tres municipios del estado Portuguesa y 72 fincas ubicadas en siete municipios del estado Barinas. En todas se produjo sorgo, a la salida de lluvias, durante 2006. Se consideraron las variables estado, municipio, ��rea cosechada, h��bridos cultivados, rendimiento y coeficiente de variaci��n (riesgo). Se emple�� distribuci��n de frecuencias de la superficie cosechada de sorgo por finca para medir la concentraci��n de la cartera y se realizaron comparaciones de promedio de rendimiento con las pruebas de t de student y de Tukey, adem��s se utiliz�� la curva normal para determinar probabilidades de rendimiento. Entre los resultados m��s importantes destacan: 1) La cartera del PEAISA, conformada por fincas peque��as y medianas, no presenta riesgo de concentraci��n en un determinado segmento de tama��o, pero la producci��n total est�� concentrada (81,2%) en el estado Barinas, 2) Aunque se ubic�� en la media nacional, se logr�� un mayor rendimiento promedio/ha de sorgo en el estado Barinas en comparaci��n con Portuguesa, con riesgo de explotaci��n similar en ambos estados, 3) El h��brido de sorgo Tecsen 120 igual�� al Chaguarama VII, pero super�� en rendimiento al Himeca 101, h��brido que pudiera ser descartado de la cartera por su bajo rendimiento y mayor riesgo de explotaci��n. Esta informaci��n se analiz�� adicionalmente con una matriz denominada productividad-riesgo, que fue un desarrollo original de este trabajo.

Correla����es genot��picas entre caracter��sticas agron��micas de sorgo gran��fero (Sorghum bicolor (L.) Moench).

2016

Development of a transformation system for sorghum (Sorghum bicolor L.)

Sorghum (Sorghum bicolor (L.) Moench) is the world���s fifth major cereal crop and holds importance as a construction material, food and fodder source. More recently, the potential of this plant as a biofuel source has been noted. Despite its agronomic importance, the use of sorghum production is being constrained by both biotic and abiotic factors. These challenges could be addressed by the use of genetic engineering strategies to complement conventional breeding techniques. However, sorghum is one of the most recalcitrant crops for genetic modification with the lack of an efficient tissue culture system being amongst the chief reasons. Therefore, the aim of this study was to develop an efficient tissue culture system for establishing regenerable embryogenic cell lines, micropropagation and acclimatisation for Sorghum bicolor and use this to optimise parameters for genetic transformation via Agrobacterium-mediated transformation and microprojectile bombardment. Using five different sorghum cultivars, SA281, 296B, SC49, Wray and Rio, numerous parameters were investigated in an attempt to establish an efficient and reproducible tissue culture and transformation system. Using immature embryos (IEs) as explants, regenerable embryogenic cell lines (ECLs) could only be established from cultivars SA281 and 296B. Large amounts of phenolics were produced from IEs of cultivars, SC49, Wary and Rio, and these compounds severely hindered callus formation and development. Cultivar SA281 also produced phenolics during regeneration. Attempts to suppress the production of these compounds in cultivars SA281 and SC49 using activated charcoal, PVP, ascorbic acid, citric acid and liquid filter paper bridge methods were either ineffective or had a detrimental effect on embryogenic callus formation, development and regeneration. Immature embryos sourced during summer were found to be far more responsive in vitro than those sourced during winter. In an attempt to overcome this problem, IEs were sourced from sorghum grown under summer conditions in either a temperature controlled glasshouse or a growth chamber. However, the performance of these explants was still inferior to that of natural summer-sourced explants. Leaf whorls, mature embryos, shoot tips and leaf primordia were found to be unsuitable as explants for establishing ECLs in sorghum cultivars SA281 and 296B. Using the florets of immature inflorescences (IFs) as explants, however, ECLs were established and regenerated for these cultivars, as well as for cultivar Tx430, using callus induction media, SCIM, and regeneration media, VWRM. The best in vitro responses, from the largest possible sized IFs, were obtained using plants at the FL-2 stage (where the last fully opened leaf was two leaves away from the flag leaf). Immature inflorescences could be stored at 25oC for up to three days without affecting their in vitro responses. Compared to IEs, the IFs were more robust in tissue culture and showed responses which were season and growth condition independent. A micropropagation protocol for sorghum was developed in this study. The optimum plant growth regulator (PGR) combination for the micropropagation of in vitro regenerated plantlets was found to be 1.0 mg/L BAP in combination with 0.5 mg/L NAA. With this protocol, cultivars 296B and SA281 produced an average of 57 and 13 off-shoots per plantlet, respectively. The plantlets were successfully acclimatised and developed into phenotypically normal plants that set seeds. A simplified acclimatisation protocol for in vitro regenerated plantlets was also developed. This protocol involved deflasking in vitro plantlets with at least 2 fully-opened healthy leaves and at least 3 roots longer than 1.5 cm, washing the media from the roots with running tap water, planting in 100 mm pots and placing in plastic trays covered with a clear plastic bag in a plant growth chamber. After seven days, the corners of the plastic cover were opened and the bags were completely removed after 10 days. All plantlets were successfully acclimatised regardless of whether 1:1 perlite:potting mix, potting mix, UC mix or vermiculite were used as potting substrates. Parameters were optimised for Agrobacterium-mediated transformation (AMT) of cultivars SA281, 296B and Tx430. The optimal conditions were the use of Agrobacterium strain LBA4404 at an inoculum density of 0.5 OD600nm, heat shock at 43oC for 3 min, use of the surfactant Pluronic F-68 (0.02% w/v) in the inoculation media with a pH of 5.2 and a 3 day co-cultivation period in dark at 22oC. Using these parameters, high frequencies of transient GFP expression was observed in IEs precultured on callus initiation media for 1-7 days as well as in four weeks old IE- and IF-derived callus. Cultivar SA281 appeared very sensitive to Agrobacterium since all tissue turned necrotic within two weeks post-exposure. For cultivar 296B, GFP expression was observed up to 20 days post co-cultivation but no stably transformed plants were regenerated. Using cultivar Tx430, GFP was expressed for up to 50 days post co-cultivation. Although no stably transformed plants of this cultivar were regenerated, this was most likely due to the use of unsuitable regeneration media. Parameters were optimised for transformation by particle bombardment (PB) of cultivars SA281, 296B and Tx430. The optimal conditions were use of 3-7 days old IEs and 4 weeks old IF callus, 4 hour pre- and post-bombardment osmoticum treatment, use of 0.6 ��m gold microparticles, helium pressure of 1500 kPa and target distance of 15 cm. Using these parameters for PB, transient GFP expression was observed for up to 14, 30 and 50 days for cultivars SA281, 296B and Tx430, respectively. Further, the use of PB resulted in less tissue necrosis compared to AMT for the respective cultivars. Despite the presence of transient GFP expression, no stably transformed plants were regenerated. The establishment of regenerable ECLs and the optimization of AMT and PB parameters in this study provides a platform for future efforts to develop an efficient transformation protocol for sorghum. The development of GM sorghum will be an important step towards improving its agronomic properties as well as its exploitation for biofuel production.

Evaluaci��n de dosis y momentos de aplicaciones de urea cuarenta y seis por ciento de nitr��geno en el sistema tradicional de producci��n del sorgo (Sorghum bicolor L.) su efecto sobre el crecimiento y rendimiento del cultivo

El presente trabajo se planific�� con el prop��sito de determinar la influencia de diferentes dosis (64.41, 128.82 y 193.23 kg/ha) y momentos de aplicaciones (100% 25 dds; 50% 25 dds; 50% 45 dds y 100 % 45 dds) de urea 46 por ciento del nitr��geno sobre el crecimiento y rendimiento del cultivo del sorgo (Sorghum bicolor L. Moench), variedad Pinolero y an��lisis econ��mico de los tratamientos en estudio, bajo las condiciones ecol��gicas de la finca La Concepci��n, Nagarote, Le��n. El ensayo se estableci�� en la siembra de Postrera de 1999 (4 de Septiembre al 24 de Diciembre de 1999), utiliz��ndose un dise��o de bloques completos al azar con arreglos en parcelas divididas y estableci��ndose cuatro repeticiones. Los resultados estad��sticos mostraron efecto real de los niveles del Factor A (dosis de urea 46 % del nitr��geno), Factor B (momentos de aplicaciones de urea) y la interacci��n AxB (tratamientos) para las variables altura de planta en cm, di��metro del tallo en cm y hojas por planta a los 35 y 60 dds. De las variables evaluadas para los componentes del rendimiento, solamente el peso de mil granos resulto ser no significativas al momento de las diferentes dosis y momento de aplicaci��n de la urea. Los resultados del an��lisis econ��mico de los tratamientos indican que cuando se pas�� del tratamiento a2b1 (128.82 kg/ha de urea aplicado 100 por ciento a los 25 dds) al a2b2; (128.82 kg/ha de urea aplicado 50 por ciento a los 25 dds y 5O por ciento a los 45 dds), se obtuvo la m��s alta rentabilidad econ��mica, con un rendimiento de 3 646 kg de grano por hect��rea y una tasa de retomo marginal de 262.21 por ciento.

An assessment of the genetic relationship between sweet and grain sorghums, within Sorghum bicolor ssp. bicolor (L.) Moench, using AFLP markers

Compared to grain sorghums, sweet sorghums typically have lower grain yield and thick, tall stalks which accumulate high levels of sugar (sucrose, fructose and glucose). Unlike commercial grain sorghum (S. bicolor ssp. bicolor) cultivars, which are usually F1 hybrids, commercial sweet sorghums were selected as wild accessions or have undergone limited plant breeding. Although all sweet sorghums are classified within S. bicolor ssp. bicolor, their genetic relationship with grain sorghums is yet to be investigated. Ninety-five genotypes, including 31 sweet sorghums and 64 grain sorghums, representing all five races within the subspecies bicolor, were screened with 277 polymorphic amplified fragment length polymorphism (AFLP) markers. Cluster analysis separated older sweet sorghum accessions (collected in mid 1800s) from those developed and released during the early to mid 1900s. These groups were emphasised in a principle component analysis of the results such that sweet sorghum lines were largely distinguished from the others, particularly by a group of markers located on sorghum chromosomes SBI-08 and SBI-10. Other studies have shown that QTL and ESTs for sugar-related traits, as well as for height and anthesis, map to SBI-10. Although the clusters obtained did not group clearly on the basis of racial classification, the sweet sorghum lines often cluster with grain sorghums of similar racial origin thus suggesting that sweet sorghum is of polyphyletic origin within S. bicolor ssp. bicolor.

Influencia de rotaci��n de cultivos y m��todos de control sobre la din��mica de las malezas y el crecimiento, desarrollo y rendimiento de los cultivos ma��z (Zea mays L.), sorgo (Sorghum bicolor L.) y pepino (Cucumis sativus L.)

En el presente estudio se analiz�� la influencia que tienen los cultivos antecesores y diferentes m��todos de control sobre lo cenosis de malezas y su influencia en el crecimiento, desarrollo y rendimiento en los cultivos de sorgo, ma��z y pepino. Dicho trabajo se estableci�� en la ��poca de primera (1990) en la hacienda ���Las mercedes���, en un dise��o de parcelas divididas en bloques completos el azar con cuatro repeticiones. Las rotaciones en estudio fueron sorgo ��� sorgo, sorgo - ma��z, soya -ma��z, soya - pepino y sorgo - pepino; los m��todos de control qu��mico, control por per��odo cr��tico y limpia peri��dica. La especie Rottboellia cochichinesis, se present�� como maleza de mayor abundancia en todas las rotaciones a excepci��n de la rotaci��n soya - repino, que la mayor abundancia la reflej�� Cyperus rotundus al momento de la cosecha. Los diferentes controles mostraron un comportamiento similar para los cultivos sorgo y ma��z en el n��mero de Individuos para R. Cochichinesis. La rotaci��n soya ��� pepino present��) la mayor cobertura a la cosecha y el control qu��mico, atribuy��ndose a que no hubo una competencia interespec��fica con el cultivo. R. Cochichinesis, se encontr�� con mayor biomasa, en todas las rotaciones. El cultivo de pepino acumul�� la mayor biomasa en el qu��mico para la especie R. Cochininesis, demostr��ndose un cambio en la asociaci��n de especies donde las po��ceas reflejaron la mayor biomasa. La menor diversidad total a la cosecha se present�� en la rotaci��n sorgo ��� sorgo y la mayor en soya ���ma��z. En sorgo, los controles per��odo cr��tico y limpia peri��dica demostraron la menor diversidad a la cosecha. En ma��z la menor diversidad se obtuvo en el control por limpia peri��dica, ese mismo efecto se observ�� para el control qu��mico en el cultivo de pepino a la cosecha. En el cultivo del sorgo no reflej�� diferencias estad��sticas significativas para las variables del crecimiento, desarrollo y rendimiento, al igual en el cultivo de ma��z excepto en los diferentes controles, para la variable peso de la mazorca. En el cultivo de pepino existe significancia estad��stica para la variable longitud de gu��a, con respecto a los controles a los 54 dds, y en las rotaciones soya ���pepino, sorgo ��� pepino para el di��metro, longitud del fruto y n��mero de frutos.

Estudio preliminar de las causas de p��rdidas de viabilidad en la semilla de sorgo T-43 Sorghum bicolor (Linn) Moench

Este trabajo se realiz�� en dos investigativas La primera estuvo orientada en determinar si el tama��o de la semilla de sorgo T-43, ten��a influencia en la viabilidad, lo cual se comprob�� a nivel de campo y laboratorio, donde los porcentajes diferencias en ambos porcentajes. Cabe hacer menci��n que los datos obtenidos no son concluyentes, por carecer de repeticiones suficientes, pero si presentan tendencias en favor de la semilla clasificada con tamiz 10, el cual mostr�� los mayores porcentajes de germinaci��n: de ello podemos deducir que la semilla para uso en la siembra se debe clasificar por tama��o. La segunda fase consisto en cosechar en tres ��pocas diferentes (tres diferentes humedades de semilla), los que se secaron al sol a 13 porciento de humedad, almacen��ndose en dos ambientes diferentes (cuarto fri��, ambiente natural), los resultados no fueron concluyentes, ya que no se obtuvieron diferencias significativas en lo que se refiere a los ambientes de almacenamiento y los momentos de recolecta; por lo que la p��rdida de viabilidad observada se atribuyen a otros factores no controlados en el curso de este trabajo. Por otra parte, la semilla se sorgo T-43, muestra su m��s alto porcentaje de germinaci��n 90,80,y 85 a los 100 d��as , con rangos de temperatura y humedad relativa de 25-27��C y 60-65 por ciento respectivamente, esto para los momentos de recolecta 27.70 y 19.37% de humedad.