Assessment of Genetic Diversity for Grain Yield and Yield Component Traits in Some Genotypes of Rice (Oryza Sativa L.)

Journal of Crop Science and Biotechnology - Even though there are abundant rice genetic resources, only a fraction is used in breeding programs leading to a narrow genetic base for improved...     

Production and testing of plants regenerated from protoplasts of photoperiod sensitive genic male sterile rice (Oryza sativa L.)

Plants were regenerated from protoplasts isolated from embryonic suspension cultures of N5047S, a photoperiod sensitive genic male sterile (PGMS) Japonica rice line. Flow cytometric analyses of nuclear DNA content identified some tetraploid regenerates whose agronomic traits could be distinguished from diploid regenerates. Pollen and female fertility of diploid protoplast-derived clones grown under different light and temperature conditions was compared. A promising PGMS protoplast clone, ZAU11S, was developed from these clones. Its male sterility was confirmed as a photoperiod × temperature interaction type. This revised version was published online in July 2006 with corrections to the Cover Date.     

Characterization of resistance of cassava genotypes to bacterial blight by evaluation of leaf and systemic symptoms in relation to yield in different ecozones

Twenty-two improved and local cassava genotypes were evaluated for their bacterial blight symptom types in reaction to infection by Xanthomonas axonopodis pv. manihotis under field conditions in the forest, forest savanna transition and wet savanna zones of Togo. High genotype × environment interactions in development of each symptom type were observed. Combining data on environments and genotypes, spot, blight and wilt symptoms were positively correlated. Analysing genotype reactions across environments, indications for independent mechanisms of resistance on leaf and stem level, varying by genotype, were found. Genotypes Main27 with resistance to spot and blight symptoms and TMS4(2)1425 with resistance to wilt symptoms are recommended to breeders to introgress their resistance characteristics. Significant negative correlations were generally observed between blight and wilt symptom development and root yield across ecozones, with blight being more important under lower, and wilt under higher inoculum pressure. Genotypes TMS30572, CVTM4, TMS92/0429 and TMS91/02316 showed low spot, blight and wilt symptoms combined with high root yield across ecozones.     

Annotated checklist and fisheries interactions of cetaceans in Togo,with evidence of Antarctic minke whale in the Gulf of Guinea

Based on strandings and captures, 9 cetacean species, including 6 odontocetes and 3 mysticetes, are documented (photos and specimens) in Togo's coastal waters (newly‐recorded species marked with an asterisk): Antarctic minke whale (Balaenoptera bonaerensis*), Bryde's whale (Balaenoptera brydei or B. edeni), humpback whale (Megaptera novaeangliae), sperm whale (Physeter macrocephalus), pygmy sperm whale (Kogia breviceps*), short‐finned pilot whale (Globicephala macrorhynchus*), pantropical spotted dolphin (Stenella attenuata*), common bottlenose dolphin (Tursiops truncatus) and common dolphin Delphinus sp. An anecdotal sighting record for killer whale (Orcinus orca) is considered reliable. The lack of Sousa teuszii records in Togo is consistent with its apparent contemporaneous absence in Ghana. The B. bonaerensis specimen, entangled in a purse seine set on small pelagics, is a first record for the Gulf of Guinea. The occurrence of this Southern Ocean species north of the equator underscores the severe gaps in our understanding of cetacean distribution off western Africa. The majority of artisanal fishermen operating in Togolese coastal waters are of Ghanaian origin and are thought to promote trade and consumption of cetacean bushmeat. Because captures are illegal, enforced with some success in the main fishing centers, covert landings of cetaceans are exceedingly difficult to monitor, quantify or sample. Concern is expressed about pollution of Togo's coastal waters with heavy metals due to phosphorite mining and export from the coastal basin near Hahotoé and Kpogamé.     

Use of the Capripoxvirus homologue of Vaccinia virus 30 kDa RNA polymerase subunit (RPO30) gene as a novel diagnostic and genotyping target: development of a classical PCR method to differentiate Goat poxvirus from Sheep poxvirus

Sheep poxvirus (SPPV), Goat poxvirus (GTPV) and Lumpy skin disease virus (LSDV) are Capripoxviruses (CaPVs) responsible for causing severe poxvirus disease in sheep, goats and cattle, respectively. Serological differentiation of CaPVs is not possible and strain identification has relied on the implicitly accepted hypothesis that the viruses show well defined host specificity. However, it is now known that cross infections can occur and authentication of identity based on the host animal species from which the strain was first isolated, is not valid and should be replaced with molecular techniques to allow unequivocal strain differentiation. To identify a diagnostic target for strain genotyping, the CaPV homologue of the Vaccinia virus E4L gene which encodes the 30 kDa DNA-dependent RNA polymerase subunit, RPO30 was analyzed. Forty-six isolates from different hosts and geographical origins were included. Most CaPVs fit into one of the three different groups according to their host origins: the SPPV, the GTPV and the LSDV group. A unique 21-nucleotide deletion was found in all SPPV isolates which was exploited to develop a RPO30-based classical PCR test to differentiate SPPV from GTPV that will allow rapid differential diagnosis of disease during CaPV outbreaks in small ruminants.     

水稻株高基因对GA3敏感性及与酶的关系

 用3对水稻植株高度近等基因对，研究了株高基因对GA₃ 敏感性和酶的影响。结果表明，株高基因在苗期对GA₃ 敏感性强弱顺序为eui>sd1>Sd1>sds(t)；其中梗稻的Sd1敏感性强于籼稻的。 用胚乳培养法快速鉴别水稻株高基因对GA₃敏感性的结果与幼苗鉴定的一致，说明这种方法是有效的。 在酶活性方面，4 d的幼苗中高秆品系的过氧化物酶活力比矮秆品系的高， 而8 d的幼苗中矮秆的活力反而比高秆的强。经GA₃处理4 d和8 d后，对GA₃敏感的品系过氧化物酶活力较低， 过氧化物酶同工酶带8和酯酶同工酶带7与株高对GA₃的敏感性有关。     

Investigation of Marek’s disease virus from chickens in central Ethiopia

Marek’s disease (MD) is a lymphoproliferative and neuropathic disease of domestic chickens and less commonly, turkeys and quails, caused by a highly contagious, cell-associated, oncogenic herpesvirus. In Ethiopia, MD is believed to be introduced with importation of exotic and crossbred to improve the poultry production and has been reported to be a potential threat to the poultry sector both in backyard and commercial farming systems. This study was aimed at isolation and molecular analysis of MD virus isolates circulating in chicken population in the central part of Ethiopia where commercial farms are populated. From September 2013 to January 2014, clinical and post-mortem examination were conducted on diseased chickens suspected of MD virus infection. Representative spleen and feather follicle samples were collected following sterile procedure, and infectious virus isolation was performed using primary chicken fibroblast cell culture. Cell culture inoculated with suspension of pathological samples developed characteristic MD virus cytopathic effect of rounding of the cells and small plaques. Further analysis of the virus was conducted by conventional PCR amplifying the ICP4 gene fragment from eleven tissue samples using MD virus specific primers. PCR products were further sequenced and analyzed. Nucleotide sequence similarity search of the local isolates resulted a high degree of sequence similarity with Gallid Herpes virus type 2 strain (Marek’s disease virus type 1, JN034558). To our knowledge, the present study is the first report conducted on virus isolation and molecular characterization of MD virus isolates circulated in Ethiopia. Eleven ICP4-like gene fragment (318 bp) sequences generated in the present study were uploaded in the public database (KU842366–76). Further research on virus isolation, genetic characterization, and infection dynamics is recommended targeting chickens of all age groups reared in different agro-ecological zones under different production system.

     

Nematicidal activity of some essential plant oils from tropical West Africa

Abstract

Plant parasitic nematodes are among the most destructive plant pathogens worldwide and their control is very challenging. Plant essential oils (EOs) have showed a great potential in nematode control. In this work, EOs from 10 aromatic plants acclimatized in Togo were assessed in vitro for their nematicidal activity on the root-knot nematode Meloidogyne incognita. EOs were subsequently analyzed by GC-MS and compounds were tested individually on nematodes. The most potent EOs were: Ocimum sanctum L., Cymbopogon schoenanthus (L.) Spreng and Cinnamomum zeylanicum Blume with EC_50/72h values of 282?±?53, 288?±?30 and 355?±?126?mg/L, respectively. The EC_50/48h values of tested compounds were 81?±?14, 117?±?33, 128?±?42, 141?±?47, 168?±?40, 216?±?86 and 235?±?43?mg/L for cinnamyl acetate, methyl eugenol, cinnamyl alcohol, acetyl eugenol, isoeugenol, eugenol and benzyl benzoate, respectively. Furthermore, we found a synergistic nematicidal activity when we combined phenylpropanoids compounds with carvone. EOs and their constituents described herein merit further studies, especially in pot experiments before serving as nematicides.     

Effects of dehydrated methanol extracts of moringa (Moringa oleifera Lam.) leaves and three of its fractions on growth performance and feed nutrient assimilation in Nile tilapia (Oreochromis niloticus (L.))

A 10-week feeding trial was conducted in a recirculation system at (27 ± 0.5 °C) to determine the effect of a methanol extract of moringa leaf meal and its different fractions. Nine isonitrogenous and isoenergetic diets containing 35% crude protein and 20 MJ kg^− 1 gross energy were used. All the experimental diets contained the same amount of fish meal. The inclusion of moringa methanol extract or of moringa extract fractions occurred by replacing the wheat meal. These diets were then denoted as diets 1 (control without any moringa product), 2, 3 (containing respectively 10.6 and 17.7% of moringa leaf meal methanol extract), 4, 5 (containing respectively 9.3 and 15.4% of a tannin-reduced fraction), 6, 7 (containing respectively 2.6 and 4.3% of a saponin-enriched fraction), 8 and 9 (containing respectively 7 and 11.6% of a tannin- and saponin-reduced fraction). Thirty six fish (four fish per treatment), with mean initial body mass of 4.9-5.2 g, were kept individually. They were fed the experimental diets at the rate of 15 g feed per kg metabolic body weight (kg^0.8) per day. Up to the 5th experimental week, no difference in growth performance was observed between all the groups. At the end of the experiment, a significant (P < 0.05) reduction of the growth performance of all the fish fed diets containing moringa 80% methanol extract or the extract fractions was generally observed when they were compared to the fish fed with the control diet. The whole body moisture, ash and crude protein of the fish fed diets containing moringa crude extract or extract fractions were not significantly different to those of the control group. Body lipid was significantly reduced for the fish fed the diets 2, 4, 5 and 9 when compared to control. Muscle and plasma cholesterol levels were generally reduced for the fish fed diets containing moringa extract and extract fractions (except for the group 5 which showed higher muscle cholesterol than that of the control). The fish in the groups 2 and 5 had significantly lower hepatosomatic indices when compared to control. On the other hand, the intestinalsomatic indices (ISI) of the groups 2, 3, 4, 5, 6 and 7 were generally higher than the control group and the groups 8 and 9 had lower ISI than the control group. The relatively high total phenolics and saponins in diets 2 to 9 may have contributed to the poorer growth performance in these groups.