Enzymatic hydrolyses of glucurono(arabino)xylan from two pasture crops, purple guinea (Panicum maximum TD58) and Napier (Pennisetum purpureum ? Pennisetum americanum) grasses

Pennisetum glaucum (Pearl millet) and P. purpureum (Napier grass) are economically important members of the genus Pennisetum. The knowledge of variability in chromosome number, size and genomic content of the species could provide clues on the mechanisms responsible for decrease or increase in genomic content in the evolutionary pathway. In the present study, twenty nine genotypes consisting of 24 pearl millet and 5 Napier grass were assessed for inter- and intra-variations in chromosome number, ploidy status and genome content. Conventional cytogenetic was used for chromosome counting and flow cytometry technique for assessing genomic contents of the genotypes. Pearl millet genotypes were diploid (2n = 14) while Napier grass were mainly polyploid (2n = 28). Despite differences in the ploidy levels, the basic chromosome number was 7. The average 2C values was 4.86 pg and 4.58 pg for pearl millet and Napier grass genotypes respectively. The DNA content per haploid cell was higher among pearl millet genotypes and the genomic size were negatively related to chromosome number and ploidy levels, meanwhile, the GC richness was directly proportional to genomic size of the genotype. The mean channel values showed that the genotypes were nuclear haploid. The present study suggests that evolution and development of polyploidy was accompanied with loss in genomic content in Napier grass. It was also discovered that pearl millet with less number of chromosome, had higher genome size than Napier grass.

Napier grass (Pennisetum purpureum Schum.) is a well-established perennial fodder crop of African origin which recently has also drawn attention for its potential as biofuel feedstock. The absence of genome information in Napier grass limits the development of sequence-specific markers which often involves a high developmental cost. This study aimed to determine cross-species transferability of microsatellite markers between pearl millet (Pennisetum glaucum L.) and Napier grass and to assess the genetic diversity of Napier grass accessions. A total of 107 pearl millet microsatellite markers were tested of which 71 markers (66 %) showed successful cross-amplification. Only 29 markers were selected to study the genetic diversity of Napier grass accessions maintained at the US Department of Agriculture-Agriculture Research Service (USDA-ARS) Tifton, GA. A total of 108 alleles were identified among 99 accessions, a pearl millet line, and a sugarcane hybrid. The average polymorphic information content (PIC) value was 0.212 per marker, while Dice coefficient of similarity ranged from 0.50 to 1.0, indicating high genetic variability among accessions. The accessions with the lowest Dice coefficient of similarity values could be useful in breeding programs. The similarity coefficient of accessions equal to 1.00 is likely an indication of a single genotype being represented by two accessions with different names. This study provides an expanded set of microsatellite markers transferable from pearl millet to Napier grass that can be used to evaluate genetic diversity in Napier grass accessions.

ABSTRACTNapier grass (Pennisetum purpureum Schum.) is an important forage crop in tropical areas although little is known about its genome information, and few molecular markers have been developed for this species. This work aimed to check the viability of cross‐species amplification of microsatellite markers between pearl millet (Pennisetum glaucum) and Napier grass and to evaluate the genetic diversity among Napier grass germplasm accessions. Fifty‐four microsatellite markers previously described in pearl millet were tested against Napier grass, and 30 markers (55.5%) showed successful cross‐amplification. From them, 18 microsatellite markers were selected to study the genetic diversity in the Embrapa Active Germplasm Bank of Napier Grass (Embrapa‐BAGCE). A total of 180 alleles were identified by these selected microsatellite markers in 107 Napier grass accessions and four pearl millet samples. The average similarity coefficient (Dice) calculated among the Embrapa‐BAGCE accessions was 0.651, ranging from 0.254 to 1.0. Some accessions showed similarity coefficients equal to one, indicating that they have common progenitors or that they might be the same accessions with different denomination. To our knowledge, this work is the first to describe microsatellite markers in Napier grass and represents a significant advance regarding the use of molecular markers in this species.

Interspecific hybrids between pearl millet (Pennisetum glaucum) and napier grass (Pennisetum purpureum) give rise to perennial fodder crops characterized by high biomass, broad clumps and good palatability. These hybrids are triploid and developed by hand pollination of napier grass pollen on pearl millet panicles. The progeny shows a high percentage of pearl millet genotype due to self-pollination in the female parent. Identification of hybrids at a young stage based on morphological characters is difficult. DNA-based molecular markers have high discriminating power and were used to assess genetic differences between hybrids and their parents. Genetic diversity was studied in 18 pearl millet × napier grass hybrids along with their parents and two released national checks using inter simple sequence repeat (ISSR) markers. Eight ISSR primers gave rise to 125 bands, of which 120 bands were polymorphic. Polymorphic information content and ISSR primer index ranged from 0.40 to 0.49 and 8.88 to 11.14, respectively. The hybrids showed the presence of unique bands, besides those shared with male and female parents. Female (pearl millet) parents formed a separate group in the dendrogram constructed based on ISSR polymorphism. The male (napier grass) parents formed a separate group along with hybrids, indicating a higher similarity of hybrids with the male parents. Principal component analysis and STRUCTURE analyses showed a similar grouping. The close resemblance of hybrids to the male parents confirmed their interspecific origin. The study revealed that ISSR marker analysis could be a quick and reliable method to identify interspecific hybrids at an early stage of growth.

ABSTRACTNapier grass and pearl millet are tropical forages from the genus Pennisetum. The variability in those species is explored in breeding programs of forages, as well as in the production of interspecific hybrids. Hybridization is a phenomenon that leads to intergenomic conflicts following the elimination of genomic sequences. In this sense, the present work aimed to study the genomic alterations occurring after interspecific hybridization of pearl millet and Napier grass with the use of cytogenetics and flow cytometry tools. These methods allowed the evaluation of chromosome morphometry, DNA content and genomic ratio in pearl millet, Napier grass and hybrids. It was observed that pearl millet and Napier grass have chromosomes with superposed size. The hybrid presents chromosomes that are smaller than expected, leading to karyotype alterations. Additionally, comparing the DNA content of parents and hybrids, loss of DNA content was demonstrated. Further, changes in the pearl millet and Napier grass genome ratio were also verified in the hybrid nucleus. Moreover, genomic rearrangements were shown to occur through karyotype alterations in the hybrid.

The physiological response of two species of grasses with C3 and C4 mechanisms syndromes, Napier grass (Pennisetum purpureum Schumach × Pennisetum glaucum (L.) R. Br) and hydric common reed grass (Phragmites australis (Cav.) Trin. Ex Steud) was examined under ambient (aCO2) and elevated CO2 (eCO2), in combination with water and temperature stress treatments. Under eCO2 and subjected to water and temperature stress, the Napier grass maintained higher daytime leaf water potential (LWP) by reducing transpiration (E) and executing larger osmotic adjustment (OA) at an average of 0.85 MPa compared with 0.42 MPa for common reed; carbon assimilation (PN) was thus higher for the Napier grass. Under aCO2 and low temperature, water stress induced no significant differences in OA between the grasses, but Napier grass still had higher PN than that of common reed. Recovery in LWP and PN following re-watering of water-stressed plants was more rapid in Napier grass than that in the common reed; the former had also higher water-use efficiency due to its low specific water use (water use/leaf area) that was just a fraction (less than 6%) that of the common reed. Exposure of common reed to eCO2 reduced stomata number, but increased it in the Napier grass, especially when subjected to water stress and high temperature. Exposure to eCO2 enhanced OA capacity and E control in Napier grass resulting in superior physiological profile over the common reed subjected to water and heat stress.

Uma das primeiras etapas quando se inicia um programa de fitorremediação de herbicidas é a avaliação da tolerância das espécies vegetais selecionadas ao respectivo contaminante. Registrado para uso no Brasil, o picloram apresenta elevada persistência no solo, podendo causar problemas de carryover e de contaminação de águas subterrâneas. Em decorrência disso, objetivou-se com este trabalho selecionar espécies que apresentem tolerância à presença do picloram no solo, para utilização futura em programas de fitorremediação de solos contaminados com este herbicida. O experimento foi realizado no período de outubro a dezembro de 2005, em casa de vegetação em Rio Verde/GO. Os tratamentos foram compostos pela combinação entre 19 espécies vegetais [Brachiaria brizantha (cv. Marandu); Brachiaria brizantha (cv. MG-5 Vitória); Brachiaria brizantha (cv. Mulato); Brachiaria decumbens; Brachiaria humidicola; Brachiaria ruziziensis; Panicum maximum (cv. Massai); Panicum maximum (cv. Mombaça); Panicum maximum (cv. Tanzânia); Pennisetum purpureum x Pennisetum glaucum - capim-elefante (cv. Paraíso); Eleusine coracana - capim-pé-de-galinha-gigante; Pennisetum glaucum - milheto (cv. ADR-300); Pennisetum glaucum - milheto (cv. ADR-500); Sorghum bicolor x Sorghum sudanense - Cover Crop; Sorghum bicolor x Sorghum sudanense sorgo (cv. Jumbo); Paspalum atratum - capim-pojuca; Zea mays - milho (híbrido Coodetec 208); Canavalia ensiformis - feijão-de-porco; e Stizolobium aterrimum - mucuna-preta] e de cinco doses do picloram (0, 80, 160, 320 e 640 g ha-1), totalizando 95 tratamentos. O delineamento experimental utilizado foi o de blocos casualizados em esquema fatorial 19 x 5, com quatro repetições. As plantas foram cultivadas em solo classificado como Latossolo Vermelho eutroférrico; após o preenchimento e umedecimento dos vasos, aplicou-se o picloram. Quinze dias após a aplicação do herbicida foi realizada a semeadura das espécies vegetais. Após a análise dos resultados, constatou-se que as espécies Zea mays - milho (híbrido Coodetec 208), Sorghum bicolor x Sorghum sudanense - Cover Crop, Eleusine coracana - capim-pé-de-galinha-gigante, Brachiaria brizantha (cv. MG-5 Vitória), Pennisetum glaucum - milheto (cv. ADR-500), Brachiaria decumbens, Brachiaria ruziziensis, Brachiaria humidicola, Pennisetum glaucum - milheto (cv. ADR-300), Brachiaria brizantha (cv. Mulato), Sorghum bicolor x Sorghum sudanense - sorgo (cv. Jumbo), Panicum maximum (cv. Tanzânia), Panicum maximum (cv. Mombaça) e Panicum maximum (cv. Massai) apresentaram tolerância à atividade residual do picloram no solo, podendo ser inseridas inicialmente para avaliação em programas de fitorremediação desse herbicida.

Se estudió la productividad de las yerbas Napier, Guinea, Para, Pangola y Melao, con distintos niveles de nitrógeno, durante distintas épocas del año, cosechándose por corte y pastoreo simulado bajo condiciones típicas de la región montañosa de Puerto Rico. La yerba Melao tuvo un rendimiento menor que las otras, las cuales tuvieron una producción similar y respondieron al nitrógeno en forma similar. La yerba Guinea produjo más que las otras en pastoreo simulado. Cuando se cosecharon por corte y se les aplicó 400 libras de nitrógeno por cuerda anualmente, las yerbas Napier, Guinea, Para, y Pangola produjeron alrededor de 24,000 libras de forraje seco por cuerda por año, con un 8 por ciento de proteína. Las yerbas produjeron menos cuando se cosecharon simulando el pastoreo que cuando se cortaban. La época del año afectó el crecimiento de las yerbas, las cuales produjeron los rendimientos más bajos en los meses de diciembre a marzo. Las aplicaciones de nitrógeno acentuaron la variación en el crecimiento durante las distintas épocas del año. El rendimiento de las yerbas Para, Guinea, Napier y Pangola aumentó rápidamente según se aumentaban los niveles de nitrógeno, por lo menos hasta 400 libras de nitrógeno por cuerda por año. Este aumento fué más notable durante las épocas de crecimiento rápido. La yerba Melao respondió sólo a la aplicación de 200 libras de nitrógeno por cuerda por año. El contenido de proteína de todas las yerbas fué similar. El contenido de proteína aumentó según aumentaba el nivel de nitrógeno; subió durante épocas de crecimiento lento, y bajó durante épocas de crecimiento rápido; y fué más bajo cuando se cortaba la yerba que cuando se simuló el pastoreo. La yerba Napier tuvo el contenido más bajo de materia seca y la Guinea el más alto de calcio y magnesio. Las cuatro yerbas de producción más alta difirieron poco en su eficiencia para utilizar el nitrógeno. La eficiencia de utilización de este nutriente fué menor bajo el pastoreo simulado, subió durante la época de crecimiento rápido y bajó según aumentaba el nivel de nitrógeno.

Fifteen genotypes of pearl millet, five genotypes of napier grass and the resultant fifteen hybrids obtained from them were evaluated for genetic variability, heritability and genetic advance. The differences between the genotypes were highly significant for all the 13 traits. Among the traits, leaf: stem ratio, dry matter yield, leaf area per clump, green fodder yield, crude protein and calcium content in pearl millet; stem girth, green fodder yield, dry matter yield, leaf: stem ratio and calcium content in napier grass and dry matter yield, leaf area per clump, green fodder yield, stem girth, number of leaves per clump, leaf: stem ratio, number of tillers per clump and crude protein in pearl millet x napier hybrids recorded high heritability coupled with high genetic advance. These traints in pearl millet, napier grass and pearl millet x napier hybrids are the most suitable for improvement through selection.

Excessive phosphorus (P) levels can disrupt nutrient balance in plants, adversely affecting growth. The molecular responses of Pennisetum species to high phosphorus stress remain poorly understood. This study examined two Pennisetum species, Pennisetum americanum × Pennisetum purpureum and Pennisetum americanum, under varying P concentrations (200, 600 and 1000 µmol·L− 1 KH2PO4) to elucidate transcriptomic alterations under high-P conditions. Our findings revealed that P. americanum exhibited stronger adaption to high-P stress compared to P. americanum× P. purpureum. Both species showed an increase in plant height and leaf P content under elevated P levels, with P. americanum demonstrating greater height and higher P content than P. americanum× P. purpureum. Transcriptomic analysis identified significant up- and down-regulation of key genes (e.g. SAUR, GH3, AHP, PIF4, PYL, GST, GPX, GSR, CAT, SOD1, CHS, ANR, P5CS and PsbO) involved in plant hormone signal transduction, glutathione metabolism, peroxisomes, flavonoid biosynthesis, amino acid biosynthesis and photosynthesis pathways. Compared with P. americanum× P. purpureum, P. americanum has more key genes in the KEGG pathway, and some genes have higher expression levels. These results contribute valuable insights into the molecular mechanisms governing high-P stress in Pennisetum species and offer implications for broader plant stress research.

This study evaluated the structure and the volume of interphase nuclei from root meristems of the genotypes of napier grass (Pennisetum purpureum), pearl millet (Pennisetum glaucum) and hybrids resultant of such breeding. In napier grass, nuclei were areticulate. Both pearl millet and the triploid hybrid had semi-reticulate nuclei; also, the hybrid presented a small proportion (6%) of areticulate nuclei. Pearl millet had the highest averages of nuclear dimensions, such as volume, diameter and radius, followed by the interspecific hybrid and napier grass. There was no intraspecific variation for the type of nuclear structure, which indicates this feature is important for cytotaxonomic studies involving the genus Pennisetum. Results demonstrated that chromatin organization in these nuclei was influenced by the number and size of chromosomes, affecting the nucleus volume in the analyzed taxa.

The productivity, in terms of carrying capacity and of beef yields, of intensively managed, well-fertilized pastures of five grasses on steep slopes in the Mountain Region of Puerto Rico with annual rainfall of 63 inches, was determined. Pangola, Guinea, and Napier grass pastures produced similar high yields, averaging 1,058 pounds of weight gain and 7,500 pounds of total digestible nutrients, equivalent to a carrying capacity of 2.4 600-pound steers per acre yearly over a 4-year period. The young cattle grazed for periods of a full year averaged 1.3 pounds of weight gain daily. No weeding was necessary and there was no problem with "manure spots" in these pastures receiving 1 ton of 14-4-10 fertilizer per acre yearly in four equal applications. There was little compaction of the soil by trampling, and loosening the surface soil after 4 years of intensive grazing did not increase yields of any of these grasses. Quality of the Pangola, Guinea, and Napier grass forage was in all cases excellent and varied little with season of the year or with grass species. Crude-protein content of samples obtained throughout the year by simulated grazing averaged 18.1 percent, phosphorus 0.22, lignin 8.1, and calcium 0.62 percent for Guinea and 0.32 percent for Napier and Pangola grasses. Para grass and molassesgrass pastures were definitely inferior to Pangola, Guinea, and Napier grasses, producing only 636 pounds of weight gain, and 5,030 pounds of total digestible nutrients per acre yearly.

SummaryThe Lepidopterous stalk borers that occur in Uganda in association with the Gramineae were studied there during 1954–1956 by collecting on all likely host-plants at two centres and by a country-wide survey in which stalk-borer damage in cereal crops was qualitatively assessed at five-mile intervals along the routes followed, and the species of borer present in such crops and, where possible, in nearby wild host-plants were determined. The commonest Noctuids were Busseola fusca (Fuller), B. segeta Bowden, Sesamia calamistis Hmps. and S. poephaga Tanas & Bowden. All these attacked sorghum, maize, sugar-cane and (except the last) finger millet (Eleusine coracana.); so also did S. botanephaga Tarns & Bowden, but only near swamps, in which it infested sedges (Cyperus spp.) and reeds (Typha australis), from which the other species were virtually absent. Only S. calamistis and S. botanephaga attacked rice. All attacked Pennisetum purpureum, Sorghum vertictlliflorum, Vossia cuspidata, and (except S. botanephaga) Panicum maximum, and also other wild grasses.B. fusca is widely distributed but most abundant in areas of intensive cultivation, where crop residues abound in which the resting larvae can survive the dry season. B. segeta is the most frequent species in Pennisetum purpureum and Panicum maximum, which are extremely common over most of the country, but is rare in cereal crops. S. calamistis (to which earlier records of S. cretica (Led.) and S. vuteria (Stoll) must be attributed) is not numerous but occurs in every district except Karamoja, where it cannot survive the dry season; and S. poephaga is known only from northern and eastern districts and is unimportant.Chilo zonellus (Swinh.), which may be a recent introduction, occurs in all the cultivated host-plants and most of the wild ones except Cyperus and Typha; it has not been found at altitudes above 4,000 ft. in the west or 5,000 ft. in the north and east, but elsewhere it is the prevalent borer and can cause severe damage in dry years and on out-of-season crops. It was the only species besides B. fusca found on bulrush millet (Pennisetum typhoides), the tough stem of which resists attack. On the western border, Eldana saccharina Wlk. attacks sorghum, maize and sugar-cane at high altitudes, and Maliarpha separatella Rag. attacks rice. A fourth Pyralid, Pectinigeria sp., occurs on maize.When small plots of host-plants were grown in a matrix of sorghum, and also in a swamp, and the whole sampled at harvest for borer infestation, all the cultivated hosts and many of the wild ones suffered some attack, the percentage of stems bored varying from 10 (finger millet) to 89 (sorghum) amongst the former, and reaching 34 (Panicum maximum), 40 (Sorghum verticilliflorum) and 50 (Pennisetum purpureum) amongst the latter. Immature stages of C. zonellus and B. fusca greatly outnumbered those of Sesamia, especially in the more heavily infested host-plants.Notes are given on the life-histories of the commoner species of borer and on their habits in the field. In the laboratory, the lengths of the life-cycles, in days, were 68–75 (B. fusca), 65–78 (B. segeta), 46–58 (S. calamistis) and 46–53 (C. zonellus). In the dry season, the larvae of B. fusca entered a resting stage, which prolonged the life-cycle to 200 days; such larvae were found only in living or dry stems of crop plants. C. zonellus and Sesamia spp. bred continuously, in the dry season the former being found chiefly in trash, stubble and volunteer tillers of sorghum, the latter in these and living stems of grasses.Of the principal cereal crops in Uganda, sorghum is the most widespread. The main crop, sown after the longer of the two dry seasons, suffers little borer attack; second crops are more severely affected, but plants with thick stems or numerous tillers nevertheless yield heavily. Finger millet is the staple food crop in the north and west; borer damage is negligible and restricted to small patches of “dead-hearts” caused by larvae from single egg-masses of S. calamistis. Maize is grown on a large scale in the districts bordering Lake Victoria and in the highlands; borer attack is usually very late and, where rainfall is adequate, appears not to afiect yields.Apanteles sesamiae Cam. and another, unidentified, Braconid probably control S. calamistis, but on the other stalk borers the incidence of parasites, which are listed, is low. Destruction of all crop residues and wild species of Sorghum around cultivated areas would considerably reduce borer attack at the beginning of the growing season, but chemical control was only partly effective and did not increase the yield.

This research is done at Taman Ternak FPPK UNIPA Manokwari that attributed to known productivity four grass kinds in fertilizing level NPK. This research uses experiment method with random group plan with factorial pattern. The treatment consists of two factors that is four grass kinds (Pennisetum purpuroides, penisetum purpureum, Sorghum Sp. Panicum maximum) and three fertilizing doses with five group, so that effort unit totals as much as 60. Defoliasi is done after aged grass 45 days. Fresh production of Pennisetum purpurhoides differ very significant than Pennisetum purpureum, Sorghum Sp. and Panicum maximum where does average successive highest fresh production Pennisetum purpurhoides that is 89696 kg/ha/defoliasi, sorghum Sp. that is 30853 kg/ha/defoliasi, Pennisetum purpureum that is 26416 kg/ha/defoliasi and Panicum maximum that is 23570 kg/ha/defoliasi. Fresh production with dose urea 100 gr + tsp 50 gr + kcl 50 gr and urea 200 gr + tsp 100 gr + kcl 100 gr differ significant than without fertilizing, where does average successive highest fresh production dose urea 200 gr + tsp 100 gr + kcl 100 gr that is 45194 kg/ha/defoliasi, dose urea 100 gr + tsp 50 gr + kcl 50 gr that is 45046 kg/ha/defoliasi and without fertilizing that is 37614 kg/ha/defoliasi. Dry matter production of Pennisetum purpuroides differ very significant than Pennisetum purpureum, Sorghum Sp. and Panicum maximum where does average successive highest dry matter production of Pennisetum purpuroides that is 13026 kg/ha/defoliasi, Sorghum Sp. that is 6555 kg/ha/defoliasi, Pennisetum purpureum that is 6243 kg/ha/defoliasi and Panicum maximum that is 4723 kg/ha/defoliasi. Average successive highest dry matter production dose urea 100 gr + tsp 50 gr + kcl 50 gr that is 7845 kg/ha/defoliasi, dose urea 200 gr + tsp 100 gr + kcl 100 gr that is 7705 kg/ha/defoliasi and without fertilizing that is 7360 kg/ha/defoliasi. Key words: Pennisetum purpuroides,Pennisetum purpureum, Sorghum Sp. Panicum maximum, fertilizing doses, NPK

Napier Pakchong (Pennisetum purpureum x Pennisetum glaucum) is the main forage grass used as a livestock food source. The application of organic fertilizer can reduce reliance on inorganic fertilizer and enhance Napier Pakchong's growth and development. This experiment was conducted in a greenhouse for four months to determine the growth rate of Napier Pakchong upon using a combination of organic fertilizers and NPK fertilizer and to identify the most suitable organic waste fertilizer with NPK for optimal growth and yield. The study employed a Completely Randomized Design (CRD) with four replications and four treatments: T1– Standard application of NPK 15:15:15 (90 g), T2 – NPK 15:15:15 (70 g) + Composted Chicken Dung (2 kg), T3 – NPK 15:15:15 (70 g) + Composted Cow Dung (2 kg), and T4 – NPK 15:15:15 (70 g) + Composted Horse Dung (2 kg). The measured parameters included live tiller count, number of leaves, fresh and dry weight (g), and soil pH. The treatment using cow dung with reduced NPK (T3) outperformed all others, exhibited 233% higher tiller count, 242% increase in fresh weight and 345% increase in dry weight compared to NPK only (T1). It can be deduced that NPK 15:15:15 (70 g) + composted cow dung (2 kg) can be the most suitable fertilizer combination to promote Napier Pakchong growth while reducing dependency on inorganic fertilizers.