scholarly journals Fruit Yield and Yield Component Means and Correlations of Four Slicing Cucumber Populations Improved through Six to Ten Cycles of Recurrent Selection

1998 ◽  
Vol 123 (3) ◽  
pp. 388-395 ◽  
Author(s):  
Christopher S. Cramer ◽  
Todd C. Wehner
Keyword(s):  
Yield Components ◽  
Recurrent Selection ◽  
Yield Component ◽  
Fruit Yield ◽  
Research Station ◽  
Strong Correlations ◽  
Marketable Yield ◽  
Horticultural Crops ◽  
Component Selection ◽  
Selection For

Increased fruit yield in slicing cucumber (Cucumis sativus L.) has been difficult to achieve since yield is quantitatively inherited with low heritability. From 1981 to 1993, four slicing cucumber populations differing in their genetic diversity (wide, medium, elite, and `Beit Alpha') were advanced through six to ten cycles of modified half-sib recurrent selection. The objectives of this research were to determine 1) the fruit yield and yield component means; 2) the correlations between yield components, between yield traits, and between components and yield; and 3) the change in means and correlations with selection for improved yield of four slicing cucumber populations. In 1994 and 1995, four families were randomly selected from three cycles (early, intermediate, and late) from each population and self-pollinated. Thirty plants from each S1 family were evaluated in 3.1-m plots in Spring and Summer 1995 and 1996 at the Horticultural Crops Research Station in Clinton, N.C. Plants were harvested and data were collected on number of branches per plant and nodes per branch, proportion of pistillate nodes, fruit set and shape, and total, early, and marketable yield. When averaged over all populations, seasons, and years, fruit yield and quality increased with selection while yield components remained unchanged with selection. Fruit yield and components differed between populations, seasons, and years. Most correlations between yield components and between yield components and fruit yield were weak, and strong correlations varied between populations, seasons, and yield components. Indirect selection of proportion of pistillate nodes has potential for improving yield for certain population-season combinations. Selection weakened many strong correlations between yield components and between yield and components. Changes in correlations often did not correspond with changes in trait means. Based on this research, selection for yield components would not be advantageous for improving fruit yield in all slicing cucumber populations. Additional yield components, yield component heritability, and better component selection methods need to be determined before component selection can be used to improve fruit yield.

scholarly journals Path Analysis of the Correlation between Fruit Number and Plant Traits of Cucumber Populations

HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 708-711 ◽  
Author(s):  
Christopher S. Cramer ◽  
Todd C. Wehner
Keyword(s):  
Yield Components ◽  
Recurrent Selection ◽  
Plant Traits ◽  
Fruit Yield ◽  
Branch Number ◽  
Fruit Number ◽  
Path Coefficients ◽  
Yield And Yield Components ◽  
Selection For ◽  
Number Of Branches

The relationships between fruit yield and yield components in several cucumber (Cucumis sativus L.) populations were investigated as well as how those relationships changed with selection for improved fruit yield. In addition, the correlations between fruit yield and yield components were partitioned into partial regression coefficients (path coefficients and indirect effects). Eight genetically distinct pickling and slicing cucumber populations, differing in fruit yield and quality, were previously subjected to modified half-sib family recurrent selection. Eight families from three selection cycles (early, intermediate, late) of each population were evaluated for yield components and fruit number per plant in four replications in each of two testing methods, seasons, and years. Since no statistical test for comparing the magnitudes of two correlations was available, a correlation (r) of 0.7 to 1.0 or –0.7 to –1.0 (r2 ≥ 0.49) was considered strong, while a correlation of –0.69 to 0.69 was considered weak. The number of branches per plant had a direct positive effect on, and was correlated (r = 0.7) with the number of total fruit per plant over all populations, cycles, seasons, years, plant densities, and replications. The number of nodes per branch, the percentage of pistillate nodes, and the percentage of fruit set were less correlated (r < |0.7|) with total fruit number per plant (fruit yield) than the number of branches per plant. Weak correlations between yield components and fruit yield often resulted from weak correlations among yield components. The correlations among fruit number traits were generally strong and positive (r ≥ 0.7). Recurrent selection for improved fruit number per plant maintained weak path coefficients and correlations between yield components and total fruit number per plant. Selection also maintained weak correlations among yield components. However, the correlations and path coefficients of branch number per plant on the total fruit number became more positive (r = 0.67, 0.75, and 0.82 for early, intermediate, and late cycles, respectively) with selection. Future breeding should focus on selecting for the number of branches per plant to improve total fruit number per plant.

scholarly journals STABILITY ANALYSIS OF YIELD AND THE COMPONENTS OF YIELD AMONG COFFEE GENOTYPES.

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 624a-624
Author(s):  
Gopi Upreti ◽  
Harry C. Bittenbender
Keyword(s):  
Yield Components ◽  
Environmental Changes ◽  
Fruit Size ◽  
Yield Component ◽  
Regression Coefficients ◽  
Phenotypic Stability ◽  
Breeding Programmes ◽  
Superior Genotypes ◽  
Selection For ◽  
The Stability

Thirteen coffee genotypes (Coffee arabica) were evaluated for yield stability in fourteen environments within Hawaii. The yield components (fruiting nodes, fruits/node, and fruit size) were also evaluated for stability in four environments. Genotype yield and component were regressed against environmental mean yield and yield component to determine the stability of yield and the components of yield. Cultivars with means above the grand mean, regression coefficients ≤ 1, and the coefficients of linear determination ≥ 50% were considered to be superior and have phenotypic stability. Stable and superior genotypes are less sensitive to environmental changes and are more adapted to favorable and unfavorable conditions than unstable genotypes. `Catuai' was stable for both yield and the components of yield (fruiting nodes, and fruits/node) which directly contribute to the yield. The genotype `SL 28' was unstable but highly responsive to favorable environments for yield as well as yield components. Selection for the stability of yield should be considered in coffee breeding programmes to develop genotypes adapted to diverse environmental conditions in Hawaii.

scholarly journals Evaluation of Yield and Yield Components of Eggplant (Solanum melongena L.) Genotypes in the Terai Region of Nepal

2020 ◽  
Vol 9 (2) ◽  
pp. 67-80
Author(s):  
Tek Prasad Gotame ◽  
Sujata Poudel ◽  
Surendra Lal Shrestha ◽  
Jiban Shrestha
Keyword(s):  
Yield Components ◽  
Agricultural Research ◽  
Fruit Size ◽  
Solanum Melongena ◽  
Research Field ◽  
Research Station ◽  
Marketable Yield ◽  
Resistant Varieties ◽  
Yield And Yield Components ◽  
Fruit Borer

The productivity of eggplant in Nepal is very low due to lack of high yielding, disease and pests resistant varieties. Eight eggplant genotypes [Parwanipur Selection -1 (PS-1), Pusa Purple Long (PPL), Pokhara Lurki, Lalgulab, Pusa Kranti, Arka Keshav, HRDBRI-012 and HRDBRI-013] were evaluated at on-station research field of Regional Agricultural Research Station, Parwanipur, Bara, and PS -1, PPL, Pokhara Lurki, Lalgulab, Pusa Kranti, and Arka Keshav were evaluated at farmers’ field, Bara and Parsa  districts from 2018 to 2019. Results of the on-station experiment showed that genotype PS-1 was the earliest maturing genotype and was harvested at 56 days after transplanting. The number of fruits per plot (9 m2 area) was 189 in Arka Keshav followed by HRDBRI012 (180) and PS-1 (179). The number of marketable fruits per plot (9 m2)  was highest in Lalgulab (166) followed by PS-1 (152). The biggest fruit size was recorded in PS-1 (130 g) followed by Pusa Kranti (121 g) and PPL (108 g). The fruit yield was recorded the highest in PS-1 (25.8 mt/ha). The genotype PS-1 was found more resistant to Fusarium wilt and shoot and fruit borer  followed by PPL. In farmers field, the highest marketable fruits per plot were produced from PPL followed by Pusa Kranti and PS-1. Similarly, the highest yield and marketable yield were also recorded in PS-1 followed by Pusa Kranti. The genotypes PS-1 and PPL were superior in terms of yield and resistance to disease and pests. Therefore, they could be a promising genotypes for central Terai region of Nepal.

Rate and Application Timing Effects on Tolerance of Covington Sweetpotato to S-Metolachlor

2013 ◽  
Vol 27 (4) ◽  
pp. 729-734 ◽  
Author(s):  
Stephen L. Meyers ◽  
Katherine M. Jennings ◽  
David W. Monks ◽  
Donnie K. Miller ◽  
Mark W. Shankle
Keyword(s):  
Linear Response ◽  
Field Studies ◽  
Application Rate ◽  
Width Ratio ◽  
Research Station ◽  
Storage Roots ◽  
Marketable Yield ◽  
Application Timing ◽  
Horticultural Crops ◽  
Quadratic Response

Field studies were conducted in 2011 and 2012 at the Horticultural Crops Research Station near Clinton, NC, to determine ‘Covington' sweetpotato tolerance to S-metolachlor rate and application timing. Treatments were a factorial arrangement of four S-metolachlor rates (0, 1.1, 2.2, or 3.4 kg ai ha−1) and six application timings (0, 2, 5, 7, 9, or 14 d after transplanting [DAP]). Immediately following application, 1.9 cm of irrigation was applied to individual plots. Sweetpotato injury was minimal for all treatments (≤ 10%). No. 1 grade sweetpotato yield displayed a negative linear response to S-metolachlor rate, and decreased from 25,110 to 20,100 kg ha−1 as S-metolachlor rate increased from 0 to 3.4 kg ha−1. Conversely, no. 1 sweetpotato yield displayed a positive linear response to S-metolachlor application timing and increased from 19,670 to 27,090 kg ha−1 as timing progressed from 0 to 14 DAP. Total marketable sweetpotato yield displayed a quadratic response to both S-metolachlor application rate and timing. Total marketable yield decreased from 44,950 to 30,690 kg ha−1 as S-metolachlor rate increased from 0 to 3.4 kg ha−1. Total marketable yield increased from 37,800 to 45,780 kg ha−1 as application timing was delayed from 0 to 14 DAP. At 1.1 kg ha−1S-metolachlor, sweetpotato storage root length to width ratio displayed a quadratic relationship to application timing and increased from 1.87 to 2.23 for applications made 0 to 14 DAP. At 2.2 kg ha−1 of S-metolachlor, sweetpotato length to width ratio displayed a quadratic response to application timing, increased from 1.57 to 2.09 for 0 to 10 DAP, and decreased slightly from 2.09 to 2.03 for 10 to 14 DAP. Application timing did not influence length to width ratio of sweetpotato storage roots for those plots treated with S-metolachlor at either 0 or 3.4 kg ha−1.

scholarly journals Heterosis in Tomato (Solanum lycopersicum L.) for Yield and Yield Component Traits

2020 ◽  
pp. 141-152
Author(s):  
Desalegn Negasa Soresa ◽  
Gomathi Nayagam ◽  
Netsanet Bacha ◽  
Zerihun Jaleta
Keyword(s):  
Solanum Lycopersicum ◽  
Yield Components ◽  
Diallel Cross ◽  
Fruit Weight ◽  
Yield Component ◽  
Fruit Yield ◽  
F1 Hybrids ◽  
Solanum Lycopersicum L ◽  
Yield Component Traits ◽  
Marketable Fruit

Estimates of heterosis for F1 hybrids over mid and better parent were computed for traits that showed significant differences between genotypes on analysis of variance. Heterosis for yield components and yield was studied using 8x8 half diallel cross in tomato (Solanum lycopersicum L.). The heterosis for yield was generally accompanied by heterosis for yield components. Heterosis for marketable fruit yield per plant ranged from (-63.4%) (P3xP8) to (33.8%) (P6xP8) and (-62.5%) (P3xP8) to (52.6%) (P5xP7), for mid parent and better parent respectively. Significant heterosis over better and mid-parent was observed for all the traits.  Best parent and Mid-parent heterosis (MPH) was highest  and in desirable direction for number of marketable fruit per plant  (29.3%; 29.2%)  in crosses ( P3xP6 for both ) and pericarp thickness  (46.3%; 57.6%) in crosses (P2xP6 and P4xP8), number of fruit cluster per plant (32.8%; 35.9%) in cross (P3xP6 for both), individual fruit weight (36.1%; 41.2%) in cross (P2xP8, P3xP5) and fruit diameter (28.4%; 28.3%) in cross (P3xP5; P2xP6), fruit length (23.07%; 20.4%)  in cross (P2xP6 for both). Out of 28 F1 crosses, positive and desirable heterosis by 10 crosses over better parent and 17 crosses over mid-parent were observed for total fruit density in tomato. An important heterosis both in heterobeltiosis and mid-parent was recorded in marketable fruit yield in ton per hectare. From all the crosses, seven crosses revealed positive from which three crosses are the most important P2xP7 (31%),  P3xP5 (20%) and P3xP6 (54%) in better parent heterosis. Similarly for mid-parent heterosis, only ten crosses out of 28 reveled positive while the rest 18 crosses showed the undesirable direction for marketable fruit yield indicating majority of the hybrids exhibited unfavorable heterotic response and only a few hybrids could be considered for selection.

The association between potato tuber yield and the components of yield in irrigated and dryland environments in the prairies

1991 ◽  
Vol 71 (1) ◽  
pp. 279-287 ◽  
Author(s):  
D. R. Lynch ◽  
G. C. Kozub
Keyword(s):  
Potato Breeding ◽  
Tuber Yield ◽  
Correlation Coefficients ◽  
Yield Component ◽  
Path Coefficient ◽  
Path Coefficient Analysis ◽  
Marketable Yield ◽  
Yield Structure ◽  
Selection For ◽  
Average Tuber Weight

A study of the yield structure of nine potato genotypes was carried out over a 3-yr period in irrigated and dryland environments in the Prairies. This was undertaken to develop an understanding of yield component interactions, which could be useful in the selection for yield in early clonal generations of the Prairie Potato Breeding Project. Path coefficient analysis was used to partition correlation coefficients among yield and yield components into direct and indirect effects. Marketable yield of tubers in the irrigated and dryland environments differed markedly as did interactions between components in determining yield. Mainstem and tuber number were associated positively with yield under irrigated but not under dryland conditions. Tuber yield was strongly associated with average tuber weight under both irrigated and dryland conditions. The study indicates that consideration of yield component interactions in early generation selection "activities" could assist in the identification of high-yielding genotypes. Key words: Path coefficient analysis, Solanum tuberosum, selection, early clonal generations

Progress and Variability After Four Cycles of Recurrent Selection in Peanut1

1992 ◽  
Vol 19 (1) ◽  
pp. 20-24 ◽  
Author(s):  
T. Halward ◽  
J. C. Wynne
Keyword(s):  
Genetic Variability ◽  
Recurrent Selection ◽  
Fruit Yield ◽  
Selection Intensity ◽  
Fruit Traits ◽  
Selection Procedures ◽  
Original Population ◽  
Arachis Hypogaea L ◽  
Selection For ◽  
Pod Length

Abstract Recurrent selection procedures are becoming more popular as a means of population improvement in self-pollinated crops. Four cycles of recurrent selection for yield in a broad-based peanut (Arachis hypogaea L.) population have been completed. The objectives of this study were to determine (a) progress made after four cycles of recurrent selection for fruit yield and (b) if sufficient variability remained in the population to permit further improvements in yield from additional cycles of selection. The 40 highest yielding lines from 100 random-paired matings, were intercrossed to produce each successive cycle, resulting in a selection intensity of 40%. Bulked seed of the parental lines from each cycle were evaluated for yield to determine progress made after four cycles of selection. The observed variation in yield among entries was mainly due to differences among cycle means. Differences among cycle means were also detected for pod length, but not for any of the other fruit traits measured. The response to selection for yield was linear with a significant (p = 0.01) and positive regression coefficient (b = 190.7 kg ha-1). Selection based on fruit yield did not significantly change the means for any of the fruit traits measured. Significant estimates of genetic variability among entries within the cycle 4 population for yield and all fruit traits measured suggest that continued progress from additional cycles of selection should be expected in this population. Greater progress from selection may have resulted had a higher selection intensity been applied. However, estimates of genetic variability would be expected to decrease with each cycle of selection as the selection intensity increases and as the genetic base of the original population narrows. In the use of a broad-based population and a relatively low selection intensity, we chose to accept a lower rate of progress/cycle for yield in order to maintain a greater level of genetic variability within the recurrent selection population.

Yield improvement in soybeans using recurrent selection

1992 ◽  
Vol 43 (1) ◽  
pp. 135 ◽  
Author(s):  
JL Rose ◽  
DG Butler ◽  
MJ Ryley
Keyword(s):  
Seed Yield ◽  
Seed Coat ◽  
Recurrent Selection ◽  
Yield Potential ◽  
Stem Rot ◽  
Research Station ◽  
Base Population ◽  
The Mean ◽  
Selection For ◽  
Evaluation Trial

The objective of this study was to evaluate the potential of recurrent selection for improving seed yield in a soybean population. Seventeen parents, chosen for their high yield potential in the sub-tropical environments of Southern and Central Queensland were intermated using a diallel cross mating system. F1 plants were intercrossed in pairs for two more generations and then allowed to self for two generations to produce the base population. The selection criterion was the seed yield of S1 lines grown at Hermitage Research Station. The selection intensity was approximately 10%. After five cycles of recurrent selection the mean yield of the population and the mean yield of the lines selected for recombination had improved by 17% and 54% respectively, in comparison with one of the original parents, Davis. Progress from recurrent selection was evaluated using fifty randomly selected lines from the base population and from each of the first three cycles of selection. The average gain per cycle in seed yield, averaged over five sites was 128 kg ha-1 or 5.4% of the yield of the base population. Greater progress (9.8% per cycle) was measured at the testing site for selection (Hermitage Research Station) which was heavily infested with phytophthora root and stem rot than at three other sites (2.7% per cycle) which has nil or low levels of disease. Broad sense heritabilities for the base population and for cycles 1, 2 and 3 in the evaluation trial were 0.34, 0.25, 0.13 and 0.14 respectively compared with a mean heritability of 0-64 for the first five cycles of the selection experiment. Expected gain from further cycles of selection was estimated at 102 kg ha-1 per cycle for three replicates at a single site. In the evaluation trial correlated responses to selection for yield were found in a number of other traits. Days to flowering was reduced by 0.8 days/cycle while days to maturity increased by 1 day/cycle. Seed shattering score was significantly reduced from 0.98 to 0-69 while there were only minor changes in plant height, lodging and seed coat quality score. Resistance to root and stem rot and seed coat mottling, due to primarily to soybean mosaic virus, were also significantly increased. The improvement in phytophthora resistance was expected as the field used for S1 yield testing had become infested with the disease. A covariate analysis indicated that about half the improvement in seed yield at the Hermitage site was due to the correlated response of increased resistance to phytophthora root and stem rot.

scholarly journals Testcross Performance of Three Selection Cycles from Four Pickling Cucumber Populations

1999 ◽  
Vol 124 (3) ◽  
pp. 257-261 ◽  
Author(s):  
Christopher S. Cramer ◽  
Todd C. Wehner
Keyword(s):  
North Carolina ◽  
Recurrent Selection ◽  
Female Parent ◽  
Fruit Shape ◽  
Fruit Yield ◽  
Population Cycle ◽  
Marketable Yield ◽  
Testcross Performance ◽  
The North ◽  
Pickling Cucumber

Progress was measured in four populations of cucumber (Cucumis sativus L.) improved by recurrent selection. The populations were the North Carolina wide base pickle (NCWBP), medium base pickle (NCMBP), elite pickle 1 (NCEP1), and hardwickii 1 (NCH1). Families from each of three cycles (early, intermediate, and late) from each population were randomly chosen and crossed with Gy 14 to produce gynoecious hybrids. Gy 14 is a gynoecious inbred used commonly as a female parent in the production of pickling cucumber hybrids. Once the plants had 10% oversized (>51 mm in diameter) fruit, plots were sprayed with paraquat to simulate once-over harvest. Selection cycles were evaluated for total, early, and marketable yield, and fruit shape. Testcross performance for fruit shape rating increased over cycles for the NCWBP and NCMBP populations when tested in either season. Testcross performance for total and early yield of the NCEP1 population tested in the spring decreased with selection, but remained constant over cycles in the summer season. The majority of yield traits in each population remained unchanged across selection cycles. Of the four populations studied, the NCMBP population had the greatest gain (7%) in testcross performance over cycles and averaged over all traits. In addition, testcross performance for fruit shape rating had the greatest gain (11%) with selection and averaged over populations. Years and seasons greatly influenced testcross performance for fruit yield and shape rating. In most instances, the fruit yield and shape of Gy 14 was higher than the testcross performance of population-cycle combinations. The performance of several families exceeded that of Gy 14 when testcross combinations were made. Those families could be selected for use in the development of elite cultivars. Chemical name used: 1,1'-dimethyl-4,4'-bipyridinium ion (paraquat).

scholarly journals Evaluation of brinjal varieties for yield, genetic variability and disease reaction grown as late rabi season crop in Assam

2018 ◽  
Author(s):  
S Gogoi ◽  
N. Mazumder ◽  
Juri Talukdar
Keyword(s):  
Bacterial Wilt ◽  
Growth Parameters ◽  
Fruit Production ◽  
Fruit Yield ◽  
Research Station ◽  
Marketable Yield ◽  
Local Cultivars ◽  
Resistant Reaction ◽  
Marketable Fruit ◽  
Wilt Incidence

Five hybrid brinjal varieties viz., Ketan, Vijay Kiron, Utkal Green, NV2035 Sarpan Bharata and two local cultivars viz., JC-1, Longai were evaluated at Horticultural Research Station, Kahikuchi, Guwahati as late rabi crop during 2014-16. Significant variation in plant growth parameters and fruit yield as well as on bacterial wilt incidence (Ralstonia solanacearum) were shown by all the varieties.Utkal Green recorded the highest per plant fruit yield (2.32 kg/plant) leading to the maximum total marketable yield (469.66 q/ha) and longer active fruiting duration (43.70 days).It also showed resistant reaction to bacterial wilt, recording only 12.44 per cent wilt incidence as compared to other varieties where it was in the range of 34.44 to 62.22 % at 55 days after transplanting. Although, Ketan and Vijay Kiron recorded moderately higher per plant fruit yield of 1.52 and 1.47 kg/plant,respectively but their total marketable fruit production reduced substantially due to high incidence of bacterial wilt (62.22 and 57.78%, respectively).The local cultivars, JC-1 and Longai exhibited moderately resistant reaction to bacterial wilt which registered 40.00 and 34.44 % , respectively.

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