Minimum Number Of Plants Research Articles

Evaluation of growth stimulants on growth and yield of cotton (Gossypium hirsutum L.)

The field experiment was performed at Adaptive Research Farm Karor, Layyah by sowing cotton variety (MNH-886) @ 25 kg ha-1. The experiment was conducted by Randomized Complete Block Design (RCBD) with a factorial arrangement and 3 replications. The fertilizer NPK was applied as per recommendation and standard agronomic practices were given at a proper time. The maximum cotton seed germination (m-2) was 37.00 with soaking the seed in potassium chloride solution. A maximum number of plants m-2 was (32.667) in treatment soaking seed in potassium chloride solution. Whereas a minimum number of plants m-2 were (20.66) in the control treatment. Maximum plant height (cm)was observed in treatment soaking the seed in potassium chloride solution. Whereas minimum plant height was recorded in the control treatment. Maximum monopodial branches were observed in treatment soaking the seed in potassium chloride solution, followed by soaking the seed in water for 12 hours (hydro-priming) which is statically at par with soaking the seed in calcium chloride solution. Whereas a maximum number of sympodial branches were recorded at soaking the seed in potassium chloride solution (23.33). Seed priming of cotton seed with water and salts have no effect on the number of squares, flowers, open bolls plant-1 and boll weight (g). Maximum average yield was (2700.00 kg ha-1) in treatment soaking seed in potassium chloride solution. Whereas minimum seed cotton yield was (2338 kg ha-1) in the control treatment. Maximum seed cotton yield was (901.07kg ha-1) in treatment soaking seed in potassium chloride solution. Whereas minimum seed cotton yield was (773.70kg ha-1) in the control treatment. Maximum seed lint yield was (1797.7 kg ha-1) in treatment soaking the seed in potassium chloride (KCl) solution. Whereas minimum seed cotton yield was (1545.6 kg ha-1) in the control treatment. Maximum seed index was (9.0167gm) in treatment soaking the seed in potassium chloride solution (KCl). Whereas the minimum seed index was (7.6133gm) in the control treatment. Seed priming of cotton seed with water and salts have no effect on the uniformity index (%), UHML fiber length, and micro narie value. Maximum GOT (%) was (46.033%) in soaking seed in potassium chloride solution (KCl). Whereas minimum GOT was (42.863%) in the control treatment.

Yields and Yield Components of Maize (Zea Mays L.) and Soybean (Glycine Max) as Affected by Different Tillage Methods

Abstract At the experiment station of the Krizevci College of Agriculture, yield and yield components of maize (Zea mays L.) and soybean (Glycine max) grown in rotation under five different methods of tillage were investigated. The aim of this study was to determine the effect of different tillage methods on yield and yield components of maize and soybean. The results and the determined number of plants per hectare of maize and soybean show that more favorable conditions for germination are in variants where ploughing performed in the autumn (variants C, D and E). During a four-year study, the minimum number of plants per hectare of maize and soybean was found in variant A. The dry season in panicle stage of maize in 2006 has lowered yields compared to 2008, and the drought in 2007 during the seed-filling period reduced the yield and the 1000 kernel weight of soybean compared with 2009 in all variants of tillage methods. The highest grain yield of maize was recorded in variant B. During 2006, with the unfavorable weather conditions, the lowest grain yield of maize was recorded in variant E with intensive tillage treatment. The highest yield of soybean was recorded in variant E, but there were no statistically significant differences compared to variants with the reduction of additional tillage interventions (variant B, C and D). With respect to maize grain and soybean seed yield, variant A was the lowest. Considering the achieved yields of maize grain, there is a possibility of reducing additional tillage interventions, whilst for achieving higher yield of soybean seed intensive tillage is recommended.

Highly efficient protocol for callogenesis, somagenesis and regeneration of Indica rice plants

In the present study, we have reported a simple, fast and efficient regeneration protocol using mature embryos as explants, and discovered its effective applicability to a range of Indica rice genotypes. We have considered the response of six varieties in the steps of the regeneration procedure. The results showed that calli were variably developed from the scutellar region of seeds and visible within 6–20 days. The highest and lowest calli induction frequency (70% and 51.66%) and number of induced calli from seeds (14 and 10.33) were observed in MR269 and MRQ74, respectively. The maximum and minimum number (7.66 and 4) and frequency of embryogenic calli (38.33% and 20%) were recorded in MR219 and MRQ74, respectively. However, the highest browning rate was observed in MR84 (87%) and the lowest rate in MRQ50 (46%). The majority of plants regenerated from embryogenic calli were obtained from MRQ50 (54%) and the minimum number of plants from MR84. In this study, the maximum numbers of plantlets were regenerated from the varieties with highest rate of embryogenic calli. Also, various varieties, including MRQ50, MR269, MR276 and MR219, were satisfactorily responding, while MRQ74 and MR84 weakly responded to the procedure. Such a simple, successful and generalized method possesses the potential to become an important tool for crop improvement and functional studies of genes in rice as a model monocot plant.

Identity and genetic relatedness of Bosnia and Herzegovina grapevine germplasm

A set of Bosnia and Herzegovina grapevine cultivars was analyzed by microsatellite markers in order to assess true cultivar identity, genetic relationships and to detect the level of genetic diversity. Survey expeditions resulted in the collection of 51 samples from 8 locations. By amplifying 22 SSR loci, 25 unique genotypes were detected, revealing new synonyms and homonyms. The number of amplified alleles was 172 and the average allele number was 7.82. The average polymorphism of analyzed loci was 71.1% and the most informative loci were VVMD28 (0.867), VChr8b (0.848), ZAG79 (0.830) and VVMD5 (0.806). Parent-offspring relationship analysis resulted in one trio elucidating the parentage of the cultivar Župljanka. A microsatellite dendrogram was constructed using the unweighted pair group method, in which genotypes clustered into two groups with subgroups, showing an overall genetic similarity of 36.8%. Assessment of true cultivar identity, identification of synonym cultivars, i.e., duplicates, will be used for establishing a grapevine germplasm collection with maximum genetic variability and minimum number of plants.

Minimum number of common bean plants per plot to assess field resistance to white mold

ABSTRACT This study aimed to determine the minimum number of plants per plot to assess the field resistance in common bean to white mold. Thirteen cultivars were inoculated with six isolates of Sclerotinia sclerotiorum and evaluated in a randomized block design with three replications and plots consisting of 1-m rows with 15 plants. Plants were inoculated by the straw test as proposed by Petzoldt and Dickson (1996), to evaluate partial resistance in a greenhouse. Eight days after inoculation the disease severity was evaluated on a 1-9 diagrammatic scale, where 1 = asymptomatic plants to 9 = plant death. To determine the minimum number of plants per plot, the following methods were used: maximum curvature, segmented linear model, quadratic segmented model and the relative CV model. There were significant differences among cultivars and isolates and no significant cultivar - isolate interaction. It was observed that eight plants per plot is an adequate number to assess the reaction of common bean to white mold.

Application of Molecular Markers Linking to Cytoplasmic Male Sterile Loci to Assist Maintainer Line Selection and Their Selection Efficiency in Welsh Onion ( Allium fistulosum L.)

Cytoplasmic male sterility exists widely in most natural populations of welsh onion ( Allium fistulosum L.), which makes it possible to breed out many male sterile lines for heterosis utilization. Unfortunately, the breeding of cytoplasmic male sterility in welsh onion has a little progress due to the limitation of its biological characteristic and traditional selection approach. To study the feasibility and the efficiency of utilizing marker assisted selection for male sterile lines in welsh onion, one SCAR marker, SCS13, and one RAPD marker, S200 2400, which could distinguish between N and S cytoplasm in several welsh onion cultivars, were identified. The two markers were then confirmed by Southern blotting, and used to screen the N or S cytoplasm of individual plants in seven welsh onion cultivars in this study. Male sterile and fertile plants were evaluated by aceto-carmine dying. The frequency of N-cytoplasmic plants and maintainer genotype was calculated in the seven open populations of welsh onion. The minimum number of plants needed to identify a maintainer was evaluated to be 95% reliable. Results showed that 20 to 80% decrease of crosses and self-crosses for identifying a maintainer genotype could be achieved by the marker-assisted selection compared with traditional selection method. It was proved that the molecular markers could precisely identify cytoplasmic types individually, performed by one generation of cross and two generations of testcrosses and self-crosses. Finally, several maintainer genotype plants were selected with the help of the two markers in the seven cultivars. The screened markers could assist and accelerate sterile and maintainer lines selection with less labor and cost.

Probability of a recombinant inbred diploid plant for two linked genes

For some discreet traits, breeders may need to break genetic linkage between a desirable trait and an undesirable trait. Breeders need to be able to determine the minimum number of plants to grow to have a specified probability of identifying at least one plant that is recombinant between two linked loci. Since 1931, recurrence equations have been available to determine the genotypic frequencies of each genotype when two loci are linked as the level of inbreeding changes. However, these genotypic frequencies have not been published in a tabular form that would be helpful to the applied plant breeder. The objectives are to: (1) provide genotypic proportions as the intensity of linkage and the level of inbreeding increases; (2) determine the most efficient method of identifying a homozygous recombinant genotype as the level of inbreeding and linkage intensity are varied. Numerical examples and formula are provided to determine the number of plants that must be grown to have a given probability of success of identifying a specified number of recombinant types. For close linkage, the number of plants that must be genotyped is greatly decreased by waiting until the population is highly inbred. Key words: Genetic recombination, inbreeding

Theoretical Analysis of the Tillering Capacity for the Lower Density of Seedling Establishment in Direct Seeding Cultivation of Rice (Oryza sativa L.).

The effects of an irregular density of seedling establishments in direct seeding cultivation of rice (Oryza sativa L.) on growth and grain yield and their relations were investigated in a paddy field (1.0 ha). The population density of established seedlings varied from 56 to 336 plants m-2, averaging 159 plants m-2, and its coefficient of variation was 38%. The coefficient of variation of the maximum number of stems per m2 decreased up to 23%, and that of the grain yield was only 17%. The maximum number of tillers per plant was negatively correlated wit}t the population density. Consequently, lower population density did not affect the grain yield. Furthermore, to analyze the tillering capacity for a lower density of seedling establishments, the nodal position of the most recent primary tiller to appear and the maximum order of tiller were examined in rice plants grown under different densities of seedling establishments. There was a tendency for the nodal position of the most recent primary tiller to appear and for the maximum order of filter to be larger as the population density decreased. Therefore the potential number of tillers per plant, which could be calculated by using these data, increased as the population density decreased. To produce 500 panicles m-2, if the percentage of fruitful culms was 65%, the minimum number of plants was calculated to be 24-46 m-2.

Single large-scale marker-assisted selection (SLS-MAS)

This paper presents a new approach for plant improvement that interactively combines the use of DNA markers and conventional breeding. This approach involves selecting plants at early generation with a fixed, favorable genetic background at specific loci, conducting a single large-scale marker-assisted selection (SLS-MAS) while maintaining as much as possible the allelic segregation in the rest of the genome. First, the identification of elite lines presenting high allelic complementarity and being outstanding for traits of interest is required to capture favorable alleles from different parental lines. Second, after identification of the most favorable genomic regions for each selected parental line, those lines are intercrossed to develop segregating populations from which plants homozygous for favorable alleles at target loci are selected. One objective of the scheme is to conduct the marker-assisted selection only once, and it requires the selection of a minimum number of plants to maintain sufficient allelic variability at the unselected loci. Therefore, the selection pressure exerted on the segregating population is quite high and the screening of large populations is required to achieve the objectives of the scheme. No selection is applied outside the target genomic regions, to maintain as much as possible the Mendelian allelic segregation among the selected genotypes. After selection with DNA markers, the genetic diversity at un-selected loci may allow breeders to generate new varieties and hybrids through conventional breeding in response to various local needs. Although the single large-scale MAS scheme described here is oriented toward maize and large-scale breeding programs with substantial resources, the flexibility of this scheme would allow breeding programs to develop options compatible with local resources.

Population Viability Analysis of American Ginseng and Wild Leek Harvested in Stochastic Environments

Many populations of threatened American ginseng (Panax quinquefolium) and vulnerable wild leek (Allium tricoccum) have declined and gone extinct because of overharvesting in Canada. We assessed the impact of harvesting on populations of these species in stochastically varying environments and estimated their extinction thresholds and minimum viable populations. With both species we used four transition matrices taken from the literature in stochastic population projections under various harvesting regimes. For American gingseng the mean population growth rate (λ) declined with increasing harvesting rate (h) according to the number of years between harvests (tr), as −0.54 htr−0.90. When plants with more than two leaves are harvested every 5 years, a harvest rate of approximately 30% was sufficient to bring the λ below the equilibrium value of 1.0. Extinction thresholds, the minimum number of plants needed to rebuild a population, varied from 30 to 90 plants, and the minimum viable population size was estimated at 170 plants. Only a dozen populations known in Canada exceed 170 plants, so most populations could not support any harvesting without serious threats to their long‐term persistence. For wild leek, two harvesting strategies were identified from confiscated, illegal harvests from Gatineau Park (Québec): (1) “choosy” harvesters collect fewer but larger bulbs, and (2) “busy” harvesters collect numerous but smaller bulbs. These data allowed simulations of more‐realistic harvesting strategies. The rate of the decline λ along the harvest gradient was faster for wild leek than for ginseng and varied with harvesting strategies. At harvesting rates between 1 and 8% the probability that λ falls below the equilibrium value was less than 5%. The extinction threshold of wild leek was estimated at 140–480 plants and the minimum viable population at 300—1030 plants, according to the threshold chosen. Remnant wild leek populations in Québec rarely contain more than a few hundred plants, indicating the serious threat commercial harvesting represents for this species. For both species we found that the whims of a stochastically varying environment significantly reduce sustainable harvest levels.

Detection of linkage between restriction fragment length polymorphism markers and quantitative traits

Methodologies commonly used to detect linkage of marker loci to loci affecting quantitative traits are discussed. It is shown that variances for the quantitative trait differ among marker genotypes when using F2 or pooled backcross data if linkage exists. Hence, to analyze this type of data by single factor ANOVA or other statistical techniques that assume a common variance is inadequate. Restriction fragment length polymorphism (RFLP) markers are a powerful tool in plant breeding but cost is an important drawback; hence, a methodology is suggested to obtain the minimum number of plants in F2 populations to detect such linkage.