scholarly journals Adaptability and stability of soybean advanced lines of semi early cycle for rust resistance

2012 ◽  
Vol 12 (1) ◽  
pp. 43-51 ◽  
Author(s):  
Juliana Araújo Santos Martins ◽  
Fernando Cézar Juliatti

This research work was carried out to verify the adaptability and phenotypic stability of soybean inbred lines of semi early cycle, using rust severity as the selection trait for partial resistance. The strains were evaluated during the growing seasons of 2007/08 and 2008/09, in the locations of Uberlândia and Uberaba, MG, Campo Alegre de Goiás and Senador Canedo, GO, using a randomized complete block design with three replications. Rust severity was evaluated by visual assessment of the leaflets at the medial third of five plants in each plot. By using disease severity, it was estimated: the mean absolute rate of disease progress (r), the area under the disease progress curve (AUDPC) and the partial resistance factor (PRF). Adaptability and stability of the strains were estimated by the methods proposed by Eberhart and Russell, as well as by the AMMI method. It was found that the strains which were the most resistant to rust, in general, also showed the best adaptability and stability.

Plant Disease ◽  
1999 ◽  
Vol 83 (8) ◽  
pp. 733-738 ◽  
Author(s):  
J. P. Wilson ◽  
R. N. Gates

The expression of partial resistance to Puccinia substriata var. indica and its contribution to digestible biomass production in forage pearl millet hybrids were evaluated in field experiments at Tifton, GA. Inbreds Tift 383, Tift 65, and nine inbreds with partial resistance selected from the cross Tift 383 × ‘ICMP 501’ were crossed to Tift 23DA4. The parental inbreds and hybrids were evaluated in natural epidemics in 1996 and 1997. Because of maturity differences among the lines, slope of the regression of logit rust severity on time (apparent infection rate) and area under the disease progress curve (AUDPC) calculated for a defined interval of plant growth (10 days before to 20 days after anthesis) and adjusted for initial rust severity at 10 days prior to anthesis were the most useful indicators of resistance. Inbred resistance was not a reliable predictor of hybrid resistance when evaluated by either variable. Hybrids were evaluated for biomass production in 1996 and 1997 in a split-plot design, with hybrids as main plots and nontreated or chlorothalonil fungicide-treated as subplots. Differences existed among hybrids for AUDPC and for digestible dry matter yield (DDMY) and its components. Over all hybrids, the response between DDMY and final rust severity was described by logarithmic regression. Two clusters of hybrids were identified by cluster analysis of disease-related data from both experiments. The cluster of susceptible hybrids tended to have a lower DDMY and were less stable over year × treatment environments than the cluster of partially resistant hybrids. Lodging in nontreated plots in 1997 primarily occurred in susceptible hybrids. Although resistance was expressed in certain hybrids, greater levels of partial resistance are needed to provide adequate protection against DDMY losses.


2013 ◽  
Vol 5 (2) ◽  
pp. 232-237
Author(s):  
Sali ALIU ◽  
Imer RUSINOVCI ◽  
Shukri FETAHU ◽  
Kemajl BISILIMI

Twelve local maize populations were evaluated at the experimental farm, University of Prishtina, Kosovo. The study was conducted to assess the magnitude of genetic variation in local maize populations for different morphological-physiological and chemical composition under field and laboratory conditions. Randomized complete block design (RCBD) with three replications was used for laying out the experiment. The results showed that there were significant differences for most morphological and physiological traits under study. The mean grain yield of all populations was 102.96 g plant-1. The protein and oil contents ranged between 11.53 to 9.43% and 4.23 to 4.87% respectively. The cellulose content varied from 6.03 to 6.37%. There were also big differences regarding phenotypic correlations. The present study revealed considerable amount of diversity among the local maize populations which could be manipulated for further improvement in maize breeding.


2017 ◽  
Vol 52 (5) ◽  
pp. 311-318
Author(s):  
Renata Gimenez Sampaio Zocche ◽  
Suziane Antes Jacobs ◽  
Norton Victor Sampaio ◽  
Velci Queiróz de Souza ◽  
Ivan Ricardo Carvalho ◽  
...  

Abstract: The objective of this work was to characterize 'Cabernet Sauvignon' wines made from grapes cultivated in the region of Bagé, RS, Brazil, during three crop seasons. A randomized complete block design was carried out with three treatments and three replicates.The evaluations were performed for the 2004, 2007, and 2008 growing seasons. 'Cabernet Sauvignon' wines of the 2004, 2008, and 2009 harvests differed for the following parameters: density, alcoholic content, total acidity, pH, reducing sugars, OD 420, 520, and 620, color intensity, total anthocyanins, total polyphenols, sodium, calcium, magnesium, manganese, copper, iron, rubidium, phosphorus, methanol, propanol, 2-methyl-l-propanol, 2, 3 - methyl-l-butanol, and sum of alcohols. 'Cabernet Sauvignon' has potential to be produced in the Bagé region, and to help it to become a wine growing region in Brazil.


Author(s):  
Yohanna J, A. ◽  
Muhammad A, M.

Field experiment was carried out during 2010 rainy season to find the effect of seeding rate on the growth and yield of okra (Abelmuschus esculentus) in Zuru Northern Guinea Savannah. Zuru is located in Zuru Local government area of Kebbi State (Latitude 11o 251 to 11o 551 North and Longitude 4o 51 to 5o 251 East of the equator). The experiment consisted of three treatments that is planting okra at one plant per stand (S1), two plants per stand (S2) and three plants per stand (S3). The experiment was laid out in randomized complete block design (RCBD) and the treatments replicated three time. The result of the experiment has shown that plant height and number of leaves/plant at 3, 6 and 9 weeks after planting (    WAP) were significantly influenced by seeding rate (P<0.05). At 3, 6 and 9 WAP tallest plants were obtained from okra plants planted at three plants/stand (27.83, 54.0 and 77.0cm) respectively followed by okra planted at two plant/stand (24.77, 50.67 and 74.33 leave/plant respectively ). However, more number of leaves/plant were obtained from okra plant at one plant/stand (9.67, 24.67 and 48.0 leaves/plant respectively) followed by okra planted at two plants/stand (8.33, 18.33 and 36.33 leaves/plant respectively). Seeding rate had significant influence on time of 50 percent flowering with one plant/stand first attaining 50 percent flowering stage just within 36.33 days followed by okra planted at two plants/stand (38 days). The mean fresh fruit yield of okra was also significantly influenced by seeding rate with the highest yield of fresh fruits obtained from three plants/stand (83.34/ha) followed by okra planted at two plants/stand (55.56/ha). However, the result of the findings recommends that, okra should be planted at two plants/stand for medium sized and marketable okra fresh fruits since at three plants/stand leads to the production of undersized fresh fruits which do not often attract customers. At one plant/stand, there seemed to be early fruiting and bigger sized fresh fruits but low total yield due to underutilization of land resource/space. Planting at one plant/stand should therefore be avoided


Author(s):  
Kareen Lynn E. Negado

This study evaluates the growth performance of lettuce (Lactuca sativa L.) utilizing various fermented products as organic fertilizers. Growth performance is determined through the plant’s weight and leaves and significant differences in growth among various treatments: (a) fish trash, (b) scrap seaweeds, (c) kangkong, and control groups urea (positive) and water (negative) was also determined. Kangkong leaves are fermented for 10 days, fish trash for 14 days and 1 month for seaweeds. Lettuce seeds are sown before transplanting (15 days after germination) into pots and placed in raised beds. Randomized complete block design is utilized in the experiment. Growth performance is measured through the number of leaves 10, 20, and 30 days after transplant and mass of plant upon harvest. After 30 days, the lettuce was harvested. Based on the findings, the soil and fermented products are acidic and the needed organic matter for optimum growth of lettuce are not sufficient as well as some nutrients of the fermented products. Among the organic fertilizers, kangkong at 30 ml performs best in terms of the growth performance of lettuce. Urea performs best in terms of the mass upon harvest. Significant differences exist in the mean number of leaves of lettuce treated with various amounts of organic fertilizers with the plants that receive urea. Lettuce produce more number of leaves and with the highest mass upon harvest when treated with urea compared with organic fertilizers applied after 30 days from transplant. Keywords: fermented kangkong; fish trash; growth performance; lettuce; scrap seaweeds


2003 ◽  
Vol 28 (3) ◽  
pp. 273-278 ◽  
Author(s):  
Cláudia V. Godoy ◽  
Lílian Amorim ◽  
Armando Bergamin Filho ◽  
Herbert P. Silva ◽  
Willian J. Silva ◽  
...  

The progress of the severity of southern rust in maize (Zea mays) caused by Puccinia polysora was quantified in staggered plantings in different geographical areas in Brazil, from October to May, over two years (1995-1996 and 1996-1997). The logistic model, fitted to the data, better described the disease progress curves than the Gompertz model. Four components of the disease progress curves (maximum disease severity; area under the disease progress curve, AUDPC; area under the disease progress curve around the inflection point, AUDPCi; and epidemic rate) were used to compare the epidemics in different areas and at different times of planting. The AUDPC, AUDPCi, and the epidemic rate were analyzed in relation to the weather (temperature, relative humidity, hours of relative humidity >90%, and rainfall) and recorded during the trials. Disease severity reached levels greater than 30% in Piracicaba and Guaíra in the plantings between December and January. Lower values of AUDPC occurred in later plantings at both locations. The epidemic rate was positively correlated (P < 0.05) with the mean daily temperatures and negatively correlated with hours of relative humidity >90%. The AUDPC was not correlated with any weather variable. The AUDPCi was negatively related to both variables connected to humidity, but not to rain. Long periods (mostly >13 h day-1) of relative humidity >90% (that corresponded to leaf wetness) occurred in Castro. Severity of southern rust in maize has always been low in Castro, thus the negative correlations between disease and the two humidity variables.


Plant Disease ◽  
2014 ◽  
Vol 98 (12) ◽  
pp. 1671-1680 ◽  
Author(s):  
William W. Turechek ◽  
Pamela D. Roberts ◽  
Philip A. Stansly ◽  
Craig G. Webster ◽  
Chandrasekar S. Kousik ◽  
...  

Squash vein yellowing virus (SqVYV) is a whitefly-transmitted ipomovirus infecting watermelon and other cucurbits that was recently introduced to Florida. Effects on watermelon are devastating, with total vine collapse, often near harvest, and fruit rendered unmarketable by brown, discolored flesh. The epidemiology of SqVYV was studied in a 1-ha field of ‘Fiesta’ watermelon over six growing seasons (I to VI) to characterize the spatial patterning of disease and temporal rate of disease progress, as well as its association with Cucurbit leaf crumple virus (CuLCrV) and Cucurbit yellow stunting disorder virus (CYSDV), two additional whitefly-transmitted viruses that often occur with SqVYV. The field was scouted at regular intervals for the length of the season for incidence of virus and number of whiteflies. Incidence of SqVYV reached 100% during seasons I, II, and V and 20% during season III. SqVYV did not occur during seasons IV and VI. SqVYV progressed in a characteristic logistic fashion in seasons I, II, and V but less so in season III. The rate of disease progress was similar for the three seasons with high disease incidence, with an average value of 0.18. A positive correlation between the area under the disease progress curve and whitefly-days was found, where both progress curves were calculated as a function of thermal time (degree days, base 0°C). SqVYV displayed significant but variable levels of aggregation, as indicated by its fit to the β-binomial distribution, the binary power law, and ordinary runs analysis. Association analysis indicated that the viruses were largely transmitted independently. Results of this study provide epidemiological information that will be useful in the development of management strategies for SqVYV-induced vine decline, and provide new information for CuLCrV and CYSDV.


Plant Disease ◽  
2001 ◽  
Vol 85 (8) ◽  
pp. 827-832 ◽  
Author(s):  
F. Á. Rodrigues Peters ◽  
L. E. Datnoff ◽  
G. H. Korndörfer ◽  
K. W. Seebold ◽  
M. C. Rush

Rice cultivars high in partial resistance (Jasmine, LSBR-5), moderately susceptible (Drew and Kaybonnet), and susceptible (Lemont and Labelle) to sheath blight were grown in a silicon-deficient Histosol with and without calcium silicate slag. The treatment with silicon increased the concentration of this element in plant tissue by 80%over all experiments. Fertilization with silicon significantly reduced the severity of sheath blight, and the total area under the vertical lesion extension progress curve on moderately susceptible and susceptible cultivars compared to those cultivars high in partial resistance without silicon. The percentage of infected tillers was significantly reduced by 82, 42, 28, 41, 26, and 17%respectively for Jasmine, LSBR-5, Drew, Kaybonnet, Lemont, and Labelle, when silicon was applied, over all experiments. Dry matter accumulation was significantly greater with added silicon. In the absence of disease, silicon enhanced dry matter accumulation by 15%over the control, whereas silicon more than doubled the mean dry matter accumulation in infected plants. The application of silicon to complement host resistance to sheath blight appears to be an effective strategy for disease management in rice, especially when the soil is low or limiting in plant-available silicon.


1997 ◽  
Vol 87 (1) ◽  
pp. 66-70 ◽  
Author(s):  
Hafiz U. Ahmed ◽  
Maria R. Finckh ◽  
Rizal F. Alfonso ◽  
Christopher C. Mundt

Experiments were conducted in farmers' fields at two locations of the irrigated lowlands of Laguna province in southern Luzon island, Philippines, during the wet seasons of 1993 and 1994. Nine rice populations were studied including pure stands, two-component mixtures, two-gene combinations of backcrossed lines containing varying combinations of the bacterial blight resistance genes Xa-4, xa-5, and Xa-10, and a non-isogenic cultivar containing Xa-4 and partial resistance to bacterial blight. The area under the disease progress curve (AUDPC) of both gene combinations studied was significantly less than the single most effective gene of each combination deployed singly. A mixture of a susceptible and a resistant line expressed an AUDPC significantly less than the mean of its component pure stands, but two other mixtures did not. The cultivar IR20, which contains both Xa-4 and partial resistance, reduced the AUDPC by about two-thirds as compared with IR-BB4, which contains Xa-4 and little or no partial resistance.


2021 ◽  
Vol 3 (3) ◽  
pp. 10-17
Author(s):  
A. Sheidu ◽  
T. M. Igyuve ◽  
A. E. Ochigbo

The study was conducted at the Teaching and Research Farms, Federal University of Agriculture, Makurdi, Nigeria. Five Cowpea genotypes (FUAMPEA-1, IT99K-573-1-1, SAMPEA-16, SAMPEA-8, BIU LOCAL) were crossed and advanced to F1, F2, BC1 and BC2 populations using bi-parental mating design. The six generations were evaluated in a Randomized Complete Block Design with three replications. Significant test of the mean performances among the entries showed significant differences among the generations for the characters studied. Wide ranges of narrow sense heritability (18 to 79%), broad sense heritability (21 to 92%) and genetic advance (5.7 to 24.1%) were obtained for characters studied. Broad and narrow sense heritability as well as genetic advance was moderate to high for most of the characters studied such as days to 50% flowering, plant height, days to pod maturity, number of seeds per pod, number of pods per plant, hundred seed weight, root length and grain yield for the three sets of cowpea crosses. The results also revealed the possibility of exploitation for grain yield and drought tolerance in the crosses studied.


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