Using unbalanced data from a barley breeding program to estimate gene effects: the Ha2, Ha4, and sdw1 genes

2004 ◽  
Vol 55 (4) ◽  
pp. 379 ◽  
Author(s):  
H. A Eagles ◽  
D. B. Moody

The effects of genes in self-pollinated crops are usually estimated from designed experiments where selection is minimised. In this study, we used a large, but unbalanced, dataset from a barley breeding program to estimate the effects of the Ha2, Ha4, and sdw1 genes on grain yield, grain weight, grain protein, malt extract, and diastatic power. The Ha2 and Ha4 genes for resistance to cereal cyst nematode were under intense selection pressure, whereas the sdw1 gene, which reduces plant height, was under mild selection pressure.From a mixed-model analysis of mainly F5-derived lines over 5 years, resistance due to the Ha2 gene was found to increase grain yields at 2 sites where the nematode was expected to be present, but not at 3 other sites. There was no significant effect of Ha4 on grain yield. Because of selection, data from later stages of evaluation were not useable for Ha2 or Ha4. From analyses of both early stage and later stages of evaluation, the semi-dwarf allele of the sdw1 gene increased grain yields at high-yielding sites, but decreased yields at low-yielding sites. The semi-dwarf allele reduced grain weight. The effects of Ha2 or Ha4 on malt extract and diastatic power were not significant, but the semi-dwarf allele at sdw1 reduced grain protein.We concluded that plant breeding data can be used to successfully estimate the effects of important genes, with bias due to selection minimised by the use of data from appropriate stages of selection and the use of appropriate statistical models.

2000 ◽  
Vol 51 (2) ◽  
pp. 247 ◽  
Author(s):  
M. Q. Lu ◽  
L. O'Brien ◽  
I. M. Stuart

Relationships between malting quality attributes and grain yield in segregating populations can profoundly influence the intensity and sequence of trait selection. Consequently, the interrelationships between malting quality parameters predicted by near infrared transmittance (NIT) spectroscopy, grain weight, and grain yield in unselected populations of F2, F3, and F4 breeding lines from 4 barley crosses were examined. The simple and partial correlations between malt extract, protein content, and diastatic power were similar to those reported in previous studies except for a positive correlation between malt extract and diastatic power in the F2 and F3 generations. This positive relationship should enhance selection for improved malting quality in breeding programs. There were no relationships between grain yield and malting quality attributes, which would have an adverse impact on the intensity and sequence of trait selection. The effect of F2 and F3 selection for malting quality on F3 and F4 yield distributions was estimated by comparing the F3 and F4 yield distributions of the entire unselected population with those for the selected populations. Individual selection and sequential independent selection in the F2 and F3 generation for malting quality parameters predicted by NIT spectroscopy and grain weight in 4 crosses generally did not alter the nature of the subsequent yield distributions, yet 78–90% of lines could be discarded and there still existed adequate genetic gain for grain yield in the retained population of potentially good malting quality lines. These results indicate that barley breeders could use NIT spectroscopy to efficiently select in the early generations for malting quality prior to the conduct of yield testing and obtain good genetic gain for both malting quality and grain yield.


1970 ◽  
Vol 6 (3) ◽  
pp. 255-261 ◽  
Author(s):  
J. F. Seitzer

SUMMARYCCC applied to bread wheat, in 1967 and 1968 as a foliar spray at 1·40 and 2·28 kg./ha. a.i., prevented and/or delayed lodging to some extent. However, this effect was small and complete control of lodging seems to be unlikely, even when using large amounts. CCC increased grain yields, by 1·5 to 10·9 qu./ha., depending on the extent to which lodging was reduced. Significant depressions in yield were obtained, presumably owing to an observed increase incidence in ear diseases, particularly Septoria nodorum. The increase in grain yield was due mainly to an increase in 1000 grain weight and grains per ear, whereas the effect on tillers per unit area was slightly negative. Where no lodging occurred, there was a slight but non-significant tendency for increasing grain yields after CCC treatment.


2021 ◽  
Vol 45 ◽  
Author(s):  
Amanda Mendes de Moura ◽  
Flávia Barbosa Silva Botelho ◽  
Laís Moretti Tomé ◽  
Cinthia Souza Rodrigues ◽  
Camila Soares Cardoso da Silva ◽  
...  

ABSTRACT In the context of plant breeding programs, it is necessary to evaluate the efficiency of genotype selection over successive years. However, evaluating the genotype selection efficiency is not an easy task, since there is not just a single way to precede it. Besides that, the programs need to be dynamic; that is, they should be able to track the introduction and discard of genotypes each year. As a result, the available data is quite unbalanced, leading to difficulties in certain analyses. Thus, the present study aims to propose some approaches to verify the genetic progress in the preliminary trial of the Federal University of Lavras (UFLA) upland rice breeding program. We utilized mixed models for grain yield and plant height. Trials were performed with a total of 120 genotypes in seven environments, defined by the interaction between locations and years. Due to the imbalance in the available data, the mixed model approach, i.e., Restricted Maximum Likelihood/Best Linear Unbiased Prediction (REML/BLUP), was adopted for the joint analysis. Besides the genetic and phenotypic parameters, the expected gains were also obtained with the selection, genetic progress, renewal rate (RR%), and dynamism of preliminary trials. The efficiency of the selection of superior genotypes per year was verified, with genetic progress favorable for reducing the medium-sized plants associated with high yield.


1986 ◽  
Vol 107 (3) ◽  
pp. 549-554
Author(s):  
S. Singh ◽  
I. S. Pawar ◽  
I. P. Singh

SUMMARYThe analysis of Perkins & Jinks (1971) was applied to 360 progeny families of three chickpea F2 triple test crosses, namely, F 378 × ICCC 1, P 1198–1 × ICCC 1 and US 613 × BG 203, to detect and measure the interaction of additive, dominance and epistatic gene effects with sowing dates. The families were grown in completely randomized blocks in three replications with two sowing dates, and data were recorded for plant height, number of branches per plant, number of days from sowing to flowering, number of days from sowing to maturity, number of pods per plant, number of grains per plant, 100-grain weight and grain yield per plant. The i type epistasis and additive genetic component were relatively more important than j and l type epistasis and dominance component, respectively. The j and l type epistasis and additive gene effects were more sensitive to environmental differences than the i type epistasis and dominance gene effects, respectively.


1984 ◽  
Vol 103 (3) ◽  
pp. 595-611 ◽  
Author(s):  
R. J. Darby ◽  
F. V. Widdowson ◽  
M. V. Hewitt

SummaryFrom 1980 to 1982 fungicide and aphioide sprays were tested in factorial combination with four amounts of nitrogen fertilizer, applied in one or two dressings to winter wheat, on three contrasting clay soils. These experiments were at Hexton (Burwell series) in Hertfordshire, at Billington (Evesham series) and at Maulden (Hanslope series) in Bedfordshire, following a 2–year break, an all-cereal rotation, and continuous wheat respectively. The nitrogen dressings were calculated after taking into account mineral N in the soil. In 1981 and 1982 soil density was measured by penetrometer. This showed compaction in soil at Maulden 28 cm deep which caused waterlogging in spring; this delayed growth which was not made good later.At Hexton a small seed rate was used; plant losses during winter were proportionally larger than elsewhere. At Billington, the maximum number of stems occurred in March and elsewhere in April. Despite these differences in seed rate and number of plants, number of ears varied little, and each year the wheat at Hexton accumulated dry matter most rapidly. The growth rate there ranged from 20·0 to 21·8 g/m2/day during the linear growth phase as compared with 14·4 to 16·6 g/m2/day at the other two sites. Giving N in two dressings rather than in one increased dry-matter yield at all sites in May, but later this benefit remained static and so became a smaller proportion of the total. Fungicides increased post-anthesis dry-matter yield by 0·75 t/ha, most of which was incorporated in the grain.Mean grain yields from 1980 to 1982 where nitrogen fertilizer was given were 9·86 t/ha at Hexton, 7·88 t/ha at Billington and 6–91 t/ha at Maulden. Additional nitrogen fertilizer always increased grain yield when fungicides and aphicides were given, but not where they were not. Grain yields in excess of 10 t/ha were achieved with numbers of ears ranging between 360 and 435/m2. The components of yield showed that grain yield was related to the number of grains per ear and 1000·grain weight, but not number of ears. Grain weight was increased by 3·1 mg by the fungicides.The fungicides controlled the diseases eyespot (Pseudocercosporella herpolrichoides), Septoria spp. and yellow and brown rust (Pucdnia striiformis and P. recondita) where they occurred, but even where these diseases were absent or at very low levels the fungicides significantly increased grain yield. At Billington and Maulden take-all (Qaeumannomyces graminis) infected between 44 and 90% of the plants and sharp eyespot (Rhizoctonia cerealis) infected from < 1 to 20% of the stems because the wheat followed cereals. Yields of straw behind the combine-harvester were from 50 to 70% of those obtained from sheaves cut at ground level.


1974 ◽  
Vol 46 (1) ◽  
pp. 11-31
Author(s):  
Kirsti Äyräväinen ◽  
Juhani Paatela

The effects of temperature and plant spacing on growth, on the distribution of biological mass within the plant, and on yield were studied with seven barley varieties at two temperatures, 10°C and 20° C, and two growth densities, 3 and 13 plants per pot. Vegetative development at 20° C was nearly twice as fast as at 10°C. After the plants had entered the reproductive phase, the difference in developmental rate became smaller. Plants grown at the lower temperature produced much higher total biological yields and grain yields than plants grown at the higher temperature. Percentage proportion of leaves was higher and proportion of culms lower at 20° C than at 10°C. Temperature had no significant effect on number of culms and 1000-grain weight. Number of grains per ear was higher at 10°C than at 20° C. Total biological yield per pot and grain yield per pot were larger when the plants were grown in dense populations. More culms and larger yields per individual plant were produced in sparse populations. Growth density did not affect the number of grains per ear. Length of ear and 1000-grain weight were larger in sparse than dense populations. Two-rowed barley varieties gave significantly higher total biological yields and slightly higher grain yields than multi-rowed varieties. There were no differences between the two types of barley in proportions of leaves, culms and roots. As expected, number of culms and 1000-grain weight were higher, and number of grains per ear was lower, in the two-rowed than in the multi-rowed varieties. Among the various yield components, number of culms explained most of the yield. The number of grains per ear explained a smaller proportion, and 1000-grain weight a larger proportion, of the yield of the two-rowed varieties than of that of the multirowed varieties. In both types of barley there was a significant positive correlation between number of culms and 1000-grain weight. The number of grains per ear was not correlated with the number of culms; neither was it correlated with 1000-grain weight. There were differences between the two-row and multi-row types in correlations between culm numbers, leaves and roots. The distribution of biological yield between various plant parts in different phases of development did not affect the grain yield.


2012 ◽  
Vol 12 (1) ◽  
pp. 25-33 ◽  
Author(s):  
Vanderley Borges ◽  
Antônio Alves Soares ◽  
Marcos Deon Vilela de Resende ◽  
Moizés de Sousa Reis ◽  
Vanda Maria de Oliveira Cornelio ◽  
...  

Data from 11 years of a breeding program for upland rice of the partner institutions Embrapa arroz e feijão, Epamig and UFLA conducted in 11 regions of Minas Gerais, were analyzed by the mixed model methodology. The genotypic correlations between environments ranged from medium to high, suggesting the predominance of simple interaction, but with differentiated ranking of genotypes at the different locations. Lines with specific performance, as well as lines of broad adaptation were identified. The performance of cultivar BRSMG Caravera, released in 2007, was superior to the others in terms of grain yield at all sites assessed, in other words, broad adaptation, in addition to a high genotypic performance.


1977 ◽  
Vol 89 (3) ◽  
pp. 751-757 ◽  
Author(s):  
D. A. Lawes

SummaryGrain yields of 14 spring oat varieties grown at two levels of nitrogen in three seasons at two locations were compared. A genotype × environment analysis demonstrated that the more recent varieties not only had higher yields but also were better adapted to high-yielding environments. Modern varieties demonstrated a yield improvement of 30% over the older varieties. Examination of components of yield by a series of simple correlations indicated that improvement in varieties by breeding has been associated with shortened straw and higher harvest indices. Within varieties, 1000-grain weight was the most stable character and harvest index the character which varied most consistently with variations in grain yield.


1993 ◽  
Vol 120 (2) ◽  
pp. 181-186 ◽  
Author(s):  
M. J. Conry ◽  
B. Dunne

SUMMARYThe effects of varying the timing of nitrogen application and the frequency of fungicide sprays on the incidence of foliar disease and on the grain yield of winter barley (cv. Panda) were investigated at two sites in Ireland over three years, 1986–88. Nitrogen application timing had little effect on the amount of foliar necrosis due to disease but delaying application of all the nitrogen until April significantly reduced grain yields in two of the three years when compared with standard split dressings in March and April. The reductions in yield reflected small differences in 1000-grain weight.The number of fungicide sprays applied had significant effects on the amount of foliar necrosis and on grain yields. One-spray and two-spray programmes increased average yield by 16 and 32%, respectively. The yield increases were attributable to more ears/m2 and larger grains (greater 1000-grain weight). Fungicides also delayed the onset and significantly reduced the amount of brackling. Delaying nitrogen application in the spring did not decrease the number of fungicide sprays required to achieve maximum yield.


Sign in / Sign up

Export Citation Format

Share Document