66 research outputs found
Genetic diversity analysis of traditional and improved cultivars of Pakistani rice ( Oryza sativa L.) using RAPD markers
The molecular marker is a useful tool for assessing genetic variations
and resolving cultivar identities. Information on genetic diversity and
relationships among rice genotypes from Pakistan is currently very
limited. The objective of this study was to evaluate the genetic
polymorphisms and identities of 10 traditional, 28 improved and 2
Japanese cultivars of rice using the random amplified polymorphic DNA
technique. Twenty-five decamer-primers could generate a total of 208
RAPD fragments, of which 186 or 89.4% were polymorphic. The number of
amplification products produced by each primer varied from 4 to 16 with
an average of 8.3 bands primer-1. The size of amplified fragments were
ranged from 200 to 4000 bp. Pair-wise Nei and Li's similarity had
estimated the range of 0.50 to 0.96 between rice cultivars. Based on
analysis performed on a similarity matrix using UPGMA, 40 cultivars
were grouped into 3 main clusters corresponding to aromatic,
non-aromatic and japonica group. There were a few of independent
cultivars. The cluster analysis had placed most of the aromatic
cultivars into a close relation showing a high level of genetic
relatedness. However, the clusters formed by the aromatic cultivars
were distinct from those of non-aromatic and japonica types.
Interestingly, a number of improved and traditional cultivars
originating from diverse sources did not form well defined groups and
were interspersed, indicating no association between the RAPD patterns
and the geographic origin of the cultivars. The information generated
from this study can be used to maximize selection of diverse parents
and broaden the germplasm base in the future of rice breeding programs
Effect of maternal yeast feeding on dam performance and serum health biomarkers of Beetal goat kids
Supplementation with dietary yeast has improved digestibility and productive performance in ruminants. In this research the primary objective was to appraise the effects of dietary yeast supplementation of female goats during the transition period on milk composition and yield and on production and serum health biomarkers of their kids. Twenty-four Beetal goats (4 ± 1.2 years) were randomly assigned to three groups, which received 0, 5, and 10 grams/animal/day of live dried yeast Saccharomyces cerevisiae for 60 days (30 days pre- and post-partum). All goats were fed 500 grams of concentrate with water and green fodder ad libitum. Milk samples were collected at 7, 14, 21, and 28 days post kidding. Kids were weighed on days 0, 7, 15, 22, and 30, and blood samples were collected on days 15 and 30 for serum metabolites (glucose, urea, cholesterol, non-esterified fatty acids (NEFA), serum total proteins, albumin, globulin, albumin to globulin ratio, serum oxidant and antioxidant activity (malondialdehyde) (MDA) and catalase), and liver enzymes aspartate aminotransferase (AST) and alanine transaminase (ALT) assessment. Milk yield was significantly (P =0.02) higher during the post-partum period in yeast-fed goats. Yeast-fed goats also produced milk containing more fat (P <0.001) and protein (P <0.001) compared with control goats. Birth weight, average daily gain, and serum health biomarkers of the kids were not influenced by the treatments. In conclusion, dietary yeast supplementation resulted in increased production performance of the dams without significant impact on their offspring.Keywords: average daily gain, catalase activity, hepatic enzymes, milk production, Saccharomyces cerevisiae, transition perio
Abiotic Stress‐Related Expressed Sequence Tags from the Diploid Strawberry Fragaria vesca
Strawberry ( spp.) is a eudicotyledonous plant that belongs to the Rosaceae family, which includes other agronomically important plants such as raspberry ( L.) and several tree-fruit species. Despite the vital role played by cultivated strawberry in agriculture, few stress-related gene expression characterizations of this crop are available. To increase the diversity of available transcriptome sequence, we produced 41,430 L. expressed sequence tags (ESTs) from plants growing under water-, temperature-, and osmotic-stress conditions as well as a combination of heat and osmotic stresses that is often found in irrigated fields. Clustering and assembling of the ESTs resulted in a total of 11,836 contigs and singletons that were annotated using Gene Ontology (GO) terms. Furthermore, over 1200 sequences with no match to available Rosaceae ESTs were found, including six that were assigned the “response to stress” GO category. Analysis of EST frequency provided an estimate of steady state transcript levels, with 91 sequences exhibiting at least a 20-fold difference between treatments. This EST collection represents a useful resource to advance our understanding of the abiotic stress-response mechanisms in strawberry. The sequence information may be translated to valuable tree crops in the Rosaceae family, where whole-plant treatments are not as simple or practical
Genetic diversity analysis of traditional and improved cultivars of Pakistani rice ( Oryza sativa L.) using RAPD markers
The molecular marker is a useful tool for assessing genetic variations
and resolving cultivar identities. Information on genetic diversity and
relationships among rice genotypes from Pakistan is currently very
limited. The objective of this study was to evaluate the genetic
polymorphisms and identities of 10 traditional, 28 improved and 2
Japanese cultivars of rice using the random amplified polymorphic DNA
technique. Twenty-five decamer-primers could generate a total of 208
RAPD fragments, of which 186 or 89.4% were polymorphic. The number of
amplification products produced by each primer varied from 4 to 16 with
an average of 8.3 bands primer-1. The size of amplified fragments were
ranged from 200 to 4000 bp. Pair-wise Nei and Li's similarity had
estimated the range of 0.50 to 0.96 between rice cultivars. Based on
analysis performed on a similarity matrix using UPGMA, 40 cultivars
were grouped into 3 main clusters corresponding to aromatic,
non-aromatic and japonica group. There were a few of independent
cultivars. The cluster analysis had placed most of the aromatic
cultivars into a close relation showing a high level of genetic
relatedness. However, the clusters formed by the aromatic cultivars
were distinct from those of non-aromatic and japonica types.
Interestingly, a number of improved and traditional cultivars
originating from diverse sources did not form well defined groups and
were interspersed, indicating no association between the RAPD patterns
and the geographic origin of the cultivars. The information generated
from this study can be used to maximize selection of diverse parents
and broaden the germplasm base in the future of rice breeding programs
Effects of herbicide Prechlor on the performance of T. aman rice
An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University
(BAU), Mymensingh during the period from July to December 2012 to find out the effect of herbicide
Prechlor 500 EC on weed control and performance of transplant aman rice. The experiment was laid out
in a randomized complete block design with four replications. The experiment consisted of two varieties
viz., BRRI dhan41 and Nizershail, and four levels of Prechlor @ 0, 0.5, 1.0 and 1.5 L ha-1. Monochoria
vaginalis, Nymphaea nouchali, Paspalum scrobiculatum, Echinochloa crusgalli and Scirpus juncodies
were the major weeds in the experimental plots. Prechlor 500EC @ 1.5 L ha-1 showed the best
performance in reducing weed density, weed dry weight and increased weed control efficiency but reduce
grain yield. Variety had significant influence on all the yield and yield contributing characters of rice.
Higher grain yield (3.09 t ha-1) was obtained from BRRI dhan41. Different levels of Prechlor also had
significant effect on yield and yield contributing characters such as number of total tillers hill-1, number of
effective tillers hill-1, panicle length, spikelets panicle-1, grains panicle-1, grain yield, straw yield and
harvest index. Prechlor @ 1.5 L ha-1 showed best performance with respect to most yield attributes, grain
and straw yields and the lowest grain yield was obtained from Prechlor @ 0 L ha-1. The interaction effects
of variety and herbicide Prechlor had significant effect on all yield attributes except plant height, effective
tillers hill-1, panicle length, 1000-grain weight and harvest index. The highest grain yield (3.62 t ha-1) was
obtained from variety BRRI dhan41 with Prechlor @ 1.5 L ha-1. The results suggest that farmers can be
advised to use herbicide Prechlor @ 1.5 L ha-1 to boost up the production of BRRI dhan41 controlling
weeds during aman season under the agro-climatic condition of the study area
Genetic diversity of Brassica rapa germplasm of Khyber Pakhtunkhwa Pakistan revealed by molecular markers
A total of 96 indigenous Brassica rapa accessions were collected from different locations of Khyber Pakhtunkhwa, Pakistan. Simple Sequence Repeats (SSR) markers were used to identify the most diverse genotypes among the collected lots. Twenty six (26) different SSR primers were used for (genetic) variability among collected genotypes. These primers were selected from literature based on their previous results. These primers produced 135 scorable bands of which 75 were polymorphic, with an average of 55.5% polymorphic loci, and reflected the broader genetic background of the collected genotypes. An average 2.88 polymorphic bands with an average PIC value of 0.49 was recorded. Unweighted Pair Group Method with Arithmetic Mean (UPGMA) divided all genotypes into three main groups. Group one contained three clusters, while group two and three had four and two clusters each. Based on the UPGMA dendrogram, genotypes collected from Kohat, Bannu, Swat and Haripur showed considerable amount of variation. From the present study, it is concluded that SSR markers can be proved as the best tool for the genetic variability of other local and exotic B. rapa genotypes
Use of superconducting magnetic energy storage device in a powersystem to permit delayed tripping
Use of a superconducting magnetic energy storage (SMES) device in an electric power system can extend the time margin required for clearing a fault without any loss of stability of the synchronous generators in the system. Necessary mathematical model and computer simulation results have been presented. A wider time margin would be beneficial in many ways, such as precluding unwanted line tripping following temporary earth fault or transient swings, deferring costly replacement of the existing relays and breakers by the faster ones, and making a fair decision on tripping, taking into consideration a large volume of on-line data, constraints and complicated policies likely to be encountered in operating a power system under deregulation or a competitive market environment
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