Effectiveness Of Selection For Yield Research Articles

Parent Progeny Regression Analysis for Yield and Yield Contributing Traits in F3 and F4 Generations in Rice (Oryza sativa L.)

The present study was carried out during kharif (June−September, 2019) and from January to mid of May 2020 at AC&RI, Madurai, Tamilnadu state, India. From the segregating populations of F3 and F4 generations of the cross ASD16×Improved Pusa Basmati 1 to estimate the effectiveness of selection for yield and its contributing traits. F3 generation was raised in single seed decent method in the non-replicated manner and line sowing was taken in F4 generation. Positively skewed and platykurtic curve was observed for the trait hundred seed weight in the both generations this result revealed that the trait was controlled by the complementary type of gene action hence showing that intense selection is needed to obtain more genetic gain from these traits. The parent progeny regression and intergenerational correlation showed positive and highly significance for the quantitative traits i.e., days to 50% flowering, number of productive tillers, number of filled grains panicle-1, and single plant yield, plant height and hundred grain weight. Narrow sense heritability was observed for the traits viz., days to 50% flowering, single plant yield, number of productive tillers, panicle length, number of filled grains panicle-1 infer that these traits carried their additive×additive component and helped in the fixation of the characters in the early generation itself.

Breeding maize for traditional and organic agriculture

Breeding maize (Zea mays L.) for traditional agriculture can increase quality and added value of agricultural products and allow the recovery of traditional foods. The objectives of this work were to evaluate improved open-pollinated populations under organic and conventional agriculture in order to determine the effects of selection for yield and flour yield and the relationship between agronomic and quality traits under both cropping systems. We have selected open-pollinated maize populations for flour yield and bakery quality under organic conditions, improved them under conventional conditions and evaluated the breeding programs under organic and conventional conditions. Breeding was efficient for grain and flour yield under organic agriculture for Meiro (an open-pollinated population with black grains) but not for the other populations neither in organic nor in conventional conditions. Yield ranks of varieties were moderately correlated under both conditions, and genotype × environment interaction (GE) was significant for most traits when the analyses of variance were made over all environments but also when organic and conventional environments were separated. GE was higher under organic agriculture. Correlations between traits were higher under conventional agriculture and there were important discrepancies between correlations in organic and conventional agriculture. We concluded that selection under conventional agriculture was efficient for one population under organic agriculture. Selection under the target environment could increase the possibilities of success.

Evaluation of dual-purpose cows on a seasonal grass-based system of milk production

In recent years the relevance of continued selection for higher milk yield alone has been questioned for three reasons (Simm, 1998): 1) the introduction of milk quotas in some countries, 2) the now well documented deleterious effect of selection for yield on health and fertility (Pryce and Veerkamp, 2001), and, 3) the increased emphasis in payment schemes in many countries on milk composition. The purpose of this study was to measure the biological efficiency of two dual-purpose breeds (Montbeliarde (MB) and Normande (NR)) relative to two Holstein-Friesian strains (upgraded Irish Holstein-Friesian (CL) and Dutch Holstein-Friesian (HF)) on a spring-calving milk production system based mainly on grazed grass as a feed.

Efficiency of early generation selections for yield and related characters in safflower (Carthamus tinctorius L.)

The efficiency of early generation selection for yield and related characters in safflower (Carthamus tinctorius L.) was studied in the F2, F3 and F4 generations. Twenty-five F2 progenies derived from various crosses were studied. In the F2 generation, number of capitula per plant (CNSP), number of seeds per capitulum (SPSP), test weight (SWSP), and seed yield (SYSP) were the criteria used for single plant selection. The analysis of variance showed significant differences for all of the characters in the F2, F3, and F4 generations. The analysis of variance in each of the selection classes showed highly significant genotypic differences. A large number of selections in the CNSP and SYSP classes showed greater yield than the check variety. In each class the mean for that particular character showed a positive shift. The observed F3 and F4 means for seed yield per plant was higher in SYSP, indicating the effectiveness of single plant selection for yield. Correlated response showed that selection for number of capitula per plant was effective for improvement of yield.

Recurrent Selfed Progeny Selection for Yield in Soybean Using Genetic Male Sterility

The value of recurrent S1 line selection using genetic male sterility to achieve intercrosses has been questioned because of reduced seed set on male‐sterile S1 progenies, which can affect the precision of yield measurements. Recurrent S1 progeny selection for yield was practiced in two soybean [Glycine max (L.) Merr.] populations (designated II and III) that segregate for genetic male sterility. Recombination of selected lines was accomplished through insect pollination, and yield evaluations of S1 families disregarded the occurrence of male‐sterile plants in the plots. This study determined (i) rates of progress from four cycles of selection on seed yield in both populations and (ii) effects of selection for yield on other agronomic traits. Yield of Population II increased 76.6 ± 23.8 kg ha‒1 cycle‒1 (b ± SE), for a 2.1% yr‒1 increase; plant height increased 5.9% and lodging decreased 8.9% over the four cycles. Selection in Population III did not produce a significant (P > 0.05) linear increase in seed yield (only 37.7 ± 55.7 kg ha‒1 cycle‒1) and there were no significant (P > 0.05) changes in other traits. The success of selection for yield in Population II but not in Population III was most likely due to differences in genetic variability and heritability between the two. Because yield improvement was significant in Population II, it was concluded that segregation of male sterility in the S1 families was not a serious impediment to the evaluation of their relative yield potentials. Thus, genetic male sterility proved to be a useful tool for recurrent yield selection because of the ease with which selected lines are intermated.

Early Generation Selection for Grain Yield in Narrow‐Leaf Lupin (Lupinus angustifolius L.)

AbstractExperiments were conducted with early segregating generations of a selected narrow‐leaf lupin cross to determine the effectiveness of selection for yield based on alternative criteria.F2 plants were selected on the basis of seed yield and several other yield‐related characters to generate separate F3 populations. Randomly selected plants from each population were grown over the summer (off‐season) in a glasshouse to generate F4 populations.Analyses of relationships between F2 plant measurements and F3 progeny mean yields revealed significant correlations only for those characters with the highest heritabilities ‐ flowering time, 100 seed weight and harvest index. However, selection for the earliest flowering F2 plants followed by selection within this group of plants with the highest number of pod bearing branches would result in the greatest increase in F3 mean yield.The F2‐derived F4 populations with the highest seed yields were those obtained by selection for total plant dry weight, number of pod bearing branches and number of pods per plant. Improvement in commercial crop yield should therefore be obtained through selection in early generations for those characters contributing to the greatest number of pods per unit area.A scheme involving selection for early flowering and high number of pod bearing branches in the F2 combined with replicated yield tests in the F4 is proposed.

Selection‐Induced Differences among Strains of Iowa Stiff Stalks Synthetic Maize1

Different recurrent selection methods have been used for the improvement of traits in maize (Zea mays L.). The relative performance of nine strains of Iowa Stiff Stalk Synthetic (BSSSCO) derived different methods of recurrent selection for different traits were determined by evaluating strains per se, diallel crosses among strains, and Sl generations of strains and strain crosses. Objectives were to determine selection. induced differences among the nine strains and the direct and indirect effects of selection for yield, grain moisture, root and stalk lodging, and dropped ears. Replicated field trials were conducted in six environments. BS13(S)C2 had the highest yield per se (7.83 Mg ha‐1) and the highest yielding $1 generation (5.82 Mg ha‐1). Inbreeding depression for yield was less for the highly selected strains and for crosses involving those strains. Selection for resistance to European corn borer (Ostrinia nubilalis Hübner) did not significantly affect yield, but selection for resistance to corn rootworm (Diabrotica virgifera Le Conte) did have a significant negative correlated effect on grain yield. Changes in frequency of additive effects due to selection for yield improvement were more important for BSI3(S)C2 (seven cycles half‐sib and two cycles S2 selection) than for BSSS(R)C8 (eight cycles reciprocal recurrent selection). Greater changes were observed in frequency of alleles with dominance effects in BSSS(R)C8 than in BS13(S)C2. After removal the effects of drift, rate of realized gain per cycle was 0.279 Mg ha‐1 (4.4%) for BS13(S)C2 and 0.259 Mg ha‐1 (4.1%) for BSSS(R)C8. Yield of the 36 strain crosses ranged from 6.10 Mg ha‐1 for BSSSCO ✕ BSSS(RW)C2 to 9.37 Mg ha‐1 for BSSS(R)C8 ✕ BS13(S)C2. Average midparent heterosis for yield was 11.7%. Yield differences among strains and level of heterosis expressed in crosses suggested selection‐induced genetic diversity among strains of BSSSCO.

Evaluation of early generation selection procedures for yield in cowpea (Vigna unguiculata (L.) Walp.)

Abstract The objectives of the study were to evaluate early-generation selection procedures for their effectiveness in isolating high-yielding lines and to ascertain the relationship between yield performance in early (F 3 ) generation and later generations (F 5 and F 8 ). Four selection procedures viz: single plant selection (SPS), single plant bulk (SPB), bulk single plant (BSP) and selected bulk (SB) were used based on F 3 yield evaluation. Lines arising from these procedures in six crosses were compared in F 8 for yield performance. Unselected lines were used as control. The differences among the four selection procedures with respect to grain yield were not significant. However, the most high-yielding lines were from the SPS procedure. The SB procedure gave the lowest number of high-yielding lines but required the least amount of land. The mean yields of F 3 lines and bulks and the yields of F 5 and F 8 derived lines were significantly correlated, r = 0.64 ∗∗ and r = 0.70 ∗∗ , respectively, indicating the effectiveness of early-generation selection for yield in cowpea.

Selection for Agronomic Characters in Hill and Row Plots of Soybeans 1

The objectives of the study were to compare the effectiveness of selection for yield, maturity, height, lodging, and phenotypic score among soybean [Glycine max (L.) Merr.] lines in hill and row plots and in random and nonrandom complete-block designs. Progeny from 50 random S3 plants of Maturity Group II were grown in two-row, unbordered plots with 69 cm between rows within the plot and 102 cm between plots and in single, unbordered hill plots spaced 102 ✕ 102 cm. A randomized complete block design was used for the row plots, and both randomized and nonrandomized complete-block designs were used for the hill plots. There was no difference in the effectiveness of selection for yield between random and nonrandom hills. The hill and row plots were equally effective in selecting the top two lines. Actual genetic gain was 2.5 q/ha for random hills, 2.8 q/ha for nonrandom hills, and 3.0 q/ha for row plots with a 10% selection intensity. Considering possible differences in the selection differential and number of years per cycle between hill and row plots, the predicted genetic gain per year was 0.6 q/ha for random hills compared with 0.4 q/ha for rows. Selection for maturity, height, lodging, and phenotypic score was similar in effectiveness for the three plot arrangements. Genotypic correlations of line performance between random and nonrandom hills had coefficients of 0.99 to 1.02 for the four characters. The genotypic correlations between hills and rows ranged from 0.89 to 0.99. Hill plots were as effective as rows for phenotypic selection of agronomically desirable genotypes. Evaluation of yield, maturity, height, lodging, or phenotypic score can be done effectively in single, unbordered hill plots. The primary advantages of hills are the reduction in number of years required for cultivar development or recurrent selection by eliminating the need for a generation of seed increase and the larger number of lines that can be tested. Nonrandom hill plots may be useful in cases where randomization prevents efficient discarding of inferior lines before harvest.

小豆の育種年限短縮に関する試験 : (II) 暖地における系統選抜の効果(昭和41年度談話会年次講演会講演要旨)

小豆の育種年限短縮に関する試験 : (II) 暖地における系統選抜の効果(昭和41年度談話会年次講演会講演要旨)

Effectiveness of Selection for Yield in Soybean Crosses by Bulk and Pedigree Systems of Breeding1

Effectiveness of Selection for Yield in Soybean Crosses by Bulk and Pedigree Systems of Breeding¹

The effects of selection for yield in wheat

The effects of selection for yield in wheat