EFFECTIVENESS OF SEVERAL SELECTION METHODS FOR GRAIN YIELD IN TWO F2 POPULATIONS OF SPRING WHEAT

1983 ◽  
Vol 63 (1) ◽  
pp. 61-66 ◽  
Author(s):  
H. G. NASS

Visual head selection by three selectors, head weight, harvest index, and random selection were evaluated for selecting high-yielding plants in two F2 populations of spring wheat (Triticum aestivum L.). Forty F2 lines of two crosses for each selection method were evaluated for yield performance in F4 during 2 yr. There was no advantage of any of the selection methods over random selection in the lower-yielding cross 1 and no advantage of the harvest index and head weight methods over visual selection in both crosses. Visual head selection produced more late-heading, tall plants, and was the most effective method in selecting for yield in cross 2. Harvest index tended towards the selection of lines with short height in cross 2. A larger number of the top 15% of F4 lines were from the high yielding cross 2, and selectors 1 and 2 chose the greatest number of superior lines.Key words: Selection methods, head weight, harvest index, grain yield, spring wheat, visual head selection.

1987 ◽  
Vol 67 (3) ◽  
pp. 605-610 ◽  
Author(s):  
H. G. NASS

Four selection procedures, to include random selection, visual head selection by two selectors, selection for large seed size, and harvest index, respectively, were evaluated for relative effectiveness in selecting high-yielding plants in F2 and F3 populations of three crosses of spring wheat (Triticum aestivum L.). Twenty-five F4-derived lines of the three crosses for each selection method were evaluated for yield performance during 2 yr of study. Selection for large seed size and visual head selection produced more late-heading, tall or high-yielding plants than the other selection methods. A larger number of F4-derived lines in the top yielding 5% and 25% within each cross was chosen by visual selection and by selection for large seed size.Key words: Selection methods, seed size, harvest index, grain yield, spring wheat, visual head selections


1980 ◽  
Vol 60 (4) ◽  
pp. 1141-1146 ◽  
Author(s):  
H. G. NASS

The use of harvest index as a selection criterion for grain yield in F2 populations of spring wheat (Triticum aestivum L.) grown at two population densities was investigated. Harvest index was useful in delineating yield differences between lines for both crosses. The F4 lines selected in F2 for a high harvest index yielded about 9% more per plot in 1978 than F4 lines having a low harvest index in F2. Generally, lines selected at the higher commercial seeding rate yielded more than lines selected at the lower plant density. In 1979, a heavy Fusarium infection reduced the mean grain yield of the F6 lines and suppressed any significant response to selection resulting from population density and harvest index in F2. While selection based on high harvest index at low population density can be used to select higher yielding plants it was not as effective as selection at high population density which more closely approximates commercial crop densities. Additional research is needed before the use of harvest index as a selection tool in wheat breeding programs can be recommended for use in Atlantic Canada.


1982 ◽  
Vol 62 (2) ◽  
pp. 285-291 ◽  
Author(s):  
R. J. BAKER

Eight cultivars of spring wheat, Triticum aestivum L., were evaluated at seeding rates of 110, 270 and 430 seeds/m2 in a total of nine experiments spanning three locations, two dates of seeding and 2 yr. Grain yield exhibited a significant cultivar × experiment × linear response to seeding rate interaction. Grain yield of Pitic 62 showed a significant decrease with increased seeding rate in one experiment while giving the greatest increase in another. Over all experiments, the highest seeding rate gave the highest grain yield. For straw yield, Chester showed the greatest response to seed rate, Canuck the least. With the exception of Canuck, which showed a significant increase in harvest index with increased seeding rate, harvest index tended to be greater at the intermediate seeding rate.


1987 ◽  
Vol 67 (1) ◽  
pp. 87-97 ◽  
Author(s):  
P. HUCL ◽  
R. J. BAKER

Spring wheat cultivars (Triticum aestivum L.) representing a century of crop breeding effort were evaluated in three rain-fed environments to determine which yield-related traits have been altered over time. Plant height and the length of the vegetative growth phase were shortened during the pre-Thatcher era. Spikelet number has been reduced but kernel weight increased during the period of cultivar development discussed herein. Tiller production has changed little since the turn of the century while spike number has been reduced slightly in the post-Thatcher period. Harvest indices increased with the introduction of Thatcher, but neither that trait nor crop grain yield have undergone consistent improvements since the 1930s. A significant cultivar × environment interaction resulted from adverse environment having a greater negative impact on grain yield of the older cultivars Red Fife and Marquis relative to their descendents. HY320, representing a potential new market class (Canadian Prairie Spring), yielded 25% more than standard height cultivars due to a higher biological yield and harvest index. Crop and spike grain yields were associated with kernel number/spike (r = 0.78,0.75) and days to spike emergence (r = 0.50,0.55), suggesting that high grain yield in this material is a function of maturity-dependent kernel production. Future improvements in grain yield might result from selection for higher harvest index since the latter trait is positively correlated with yield (r = 0.63) but not associated with maturity (−0.17).Key words: Old cultivars, spring wheat, yield components, harvest index, cultivar × environment interaction


Author(s):  
А. I. Grabovets ◽  
V. P. Kadushkina ◽  
S. А. Kovalenko

With the growing aridity of the climate on the Don, it became necessary to improve the methodology for conducting the  breeding of spring durum wheat. The main method of obtaining the source material remains intraspecific step hybridization. Crossings were performed between genetically distant forms, differing in origin and required traits and properties. The use of chemical mutagenesis was a productive way to change the heredity of genotypes in terms of drought tolerance. When breeding for productivity, both in dry years of research and in favorable years, the most objective markers were identified — the size of the aerial mass, the mass of grain per plant, spike, and harvest index. The magnitude of the correlation coefficients between the yield per unit area and the elements of its structure is established. It was most closely associated with them in dry years, while in wet years it decreased. Power the correlation of the characteristics of the pair - the grain yield per square meter - the aboveground biomass averaged r = 0.73, and in dry years it was higher (0.91) than in favorable ones (0.61 - 0.70) , between the harvest and the harvest index - r = 0.81 (on average). In dry years, the correlation coefficient increased to 0.92. Research data confirms the greatest importance of the mass of grain from one ear and the plant in the formation of grain yield per unit area in both dry and wet years. In dry years, the correlation coefficient between yield and grain mass per plant was on average r = 0.80; in favorable years, r = 0.69. The relationship between yield and grain mass from the ear was greater — r = 0.84 and r = 0.82, respectively. Consequently, the breeding significance of the aboveground mass and the productivity of the ear, as a criterion for the selection of the crop, especially increases in the dry years. They were basic in the selection.


1990 ◽  
Vol 70 (1) ◽  
pp. 51-60 ◽  
Author(s):  
D. T. GEHL ◽  
L. D. BAILEY ◽  
C. A. GRANT ◽  
J. M. SADLER

A 3-yr study was conducted on three Orthic Black Chernozemic soils to determine the effects of incremental N fertilization on grain yield and dry matter accumulation and distribution of six spring wheat (Triticum aestivum L.) cultivars. Urea (46–0–0) was sidebanded at seeding in 40 kg N ha−1 increments from 0 to 240 kg ha−1 in the first year and from 0 to 200 kg ha−1 in the 2 subsequent years. Nitrogen fertilization increased the grain and straw yields of all cultivars in each experiment. The predominant factor affecting the N response and harvest index of each cultivar was available moisture. At two of the three sites, 91% of the interexperiment variability in mean maximum grain yield was explained by variation in root zone moisture at seeding. Mean maximum total dry matter varied by less than 12% among cultivars, but mean maximum grain yield varied by more than 30%. Three semidwarf cultivars, HY 320, Marshall and Solar, had consistently higher grain yield and grain yield response to N than Glenlea and Katepwa, two standard height cultivars, and Len, a semidwarf. The mean maximum grain yield of HY 320 was the highest of the cultivars on test and those of Katepwa and Len the lowest. Len produced the least straw and total dry matter. The level of N fertilization at maximum grain yield varied among cultivars, sites and years. Marshall and Solar required the highest and Len the lowest N rates to achieve maximum grain yield. The year-to-year variation in rates of N fertilization needed to produce maximum grain yield on a specific soil type revealed the limitations of N fertility recommendations based on "average" amounts and temporal distribution of available moisture.Key words: Wheat (spring), N response, standard height, semidwarf, grain yield


2009 ◽  
Vol 89 (6) ◽  
pp. 1099-1106 ◽  
Author(s):  
R S Sadasivaiah ◽  
R J Graf ◽  
H S Randhawa ◽  
B L Beres ◽  
S M Perkovic ◽  
...  

Sadash is a soft white spring wheat (Triticum aestivum L.) that meets the end-use quality specifications of the Canada Western Soft White Spring class. Sadash is well-adapted to the wheat-growing regions of southern Alberta and southern Saskatchewan. Based on data from the Western Soft White Spring Wheat Cooperative Registration Test from 2003 to 2005, Sadash exhibited high grain yield, mid-season maturity, semi-dwarf stature with very strong straw, and good resistance to shattering. Sadash expressed resistance to the prevalent races of stem rust and powdery mildew, intermediate resistance to loose smut, moderate susceptibility to leaf rust and common bunt, and susceptibility to Fusarium head blight. Based on end-use quality analysis performed at the Grain Research Laboratory of the Canadian Grain Commission, Sadash had improved test weight over the check cultivars AC Reed and AC Phil and similar milling and baking performance.Key words: Triticum aestivum L., cultivar description, wheat (soft white spring), grain yield, quality, disease resistance


2020 ◽  
Vol 73 (2) ◽  
pp. 9131-9141
Author(s):  
Zine El Abidine Fellahi ◽  
Abderrahmane Hannachi ◽  
Hamenna Bouzerzour

This study aimed at evaluating the expected gains from selection obtained based upon direct, indirect, and index-based selection in a set of 599 bread wheat lines. The experiment was carried out at the experimental field of INRAA institute, Setif research unit (Algeria), in a Federer augmented block design including three controls. A wide range of genetic variability was observed among lines for the eleven traits assessed. The results indicated that index-based selection and selection based on grain yield expressed higher expected genetic gain than direct and indirect mono-trait-based selection. The best 15 selected lines exhibited higher grain yield than the control varieties, and they were clustered in three groups that contrasted mainly for the flag-leaf area, thousand-kernel weight, biomass, and harvest index. The index-based selection appears as a useful tool for the rapid selection of early filial generations, enriching selected breeding materials with desirable alleles and reducing the number of years required to combine these traits in elite varieties.


1992 ◽  
Vol 72 (2) ◽  
pp. 459-463 ◽  
Author(s):  
H. W. Cutforth ◽  
F. Selles

A field study was carried out to determine the effects of seed row configuration on days to maturity, water use and grain yield of spring wheat (Triticum aestivum L. ’Leader’) grown in a semiarid environment. From 1986 to 1989, Leader spring wheat was seeded at Swift Current, Saskatchewan in north-south equidistant-rows (25-cm row spacing) and paired-rows (two rows 10 cm apart with 50 cm between the centre of each paired row). Seed and fertilizer were applied at recommended rates for the Brown soil zone. There were no significant differences (P > 0.10) in grain yield, water use or days to maturity between equidistant-row and paired-row seeding. The data suggest that under the environmental conditions of the Brown soil zone paired-row seeding may have no agronomic advantage over equidistant-row seeding.Key words: Paired-row seeding, water use, grain yield, spring wheat


2007 ◽  
Vol 58 (8) ◽  
pp. 816 ◽  
Author(s):  
P. M. Damon ◽  
Z. Rengel

A novel approach to the sustainable management of potassium (K) resources in agro-ecosystems is through better exploitation of genetic differences in the K efficiency of crop plants. Potassium efficiency is a measure of genotypic tolerance to soils with low potassium availability and can be quantified as the K efficiency ratio (the ratio of growth at deficient and adequate K supply). This study investigated the magnitude of variation in K efficiency among wheat (Triticum aestivum L.) genotypes grown in a glasshouse and in the field. Genotypes differed significantly in response to low soil K availability in terms of shoot biomass during the vegetative growth phase and grain yield at maturity under glasshouse (144 genotypes) and field (89 genotypes) conditions. K-efficient and K-inefficient genotypes were identified. The main factor determining K efficiency for grain yield was the capacity of genotypes to maintain a high harvest index (grain yield/total shoot weight) at deficient K supply. Genotypes that had reduced harvest index under deficient K supply were K-inefficient. Capacity to tolerate low concentrations of K in shoot tissue where K supply was deficient was also important in determining K efficiency for grain yield. Potassium-efficient genotypes have the potential to enhance the productivity and sustainability of cereal cropping systems.


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