Yield Contributing Traits Research Articles

Assessment of Heritability and Genetic Variabilty for Morphological and Yield Contributing Traits in Open Pollinated Maize Varieties

The knowledge of heritability helps the plant breeder to understand the performance of an attribute under consideration in next generation. Fourteen genotypes including one local check were assessed at the experimental farm of The University of Agriculture, Peshawar during spring 2016. The experiment was laid out in randomized complete block design with three replications. Analysis of variance showed highly significant differences (P≤0.01) for days to anthesis, days to silking, plant height, ear height, cob length, kernel rows cob-1 and 100-kernel weight, whereas grain yield revealed non-significant differences (P>0.05) among the genotypes evaluated. Genotypes, PSCV-9, PSCV-11, PSCV-13 and Azam as a check showed minimum days to anthesis (77.33), while minimum days to silking (79.33) were exhibited by Azam as a check. Genotype, PSCV-8 showed minimum plant height (107.13 cm) and ear height (41.73 cm), while maximum plant height (147.33 cm) and ear height (70.86 cm) was observed for PSCV-12. Genotype, PSCV-8 showed minimum ear length (17.28 cm), while maximum ear length (22.47 cm) was observed for PSCV-4. Minimum number of kernel rows cob-1 (12.33) were observed for PSCV-8, while maximum number of kernel rows cob-1 (15.33) were observed for PSCV-4. Minimum 100-kernel weight (28 g) was observed for PSCV-5 and Azam as a check, while maximum 100-kernel weight (38 g) was observed for PSCV-3. Low to moderate broad sense heritability estimates were observed for all the traits except for days to anthesis and days to silking which showed high to moderate heritability estimates. The present study revealed considerable amount of diversity among open pollinated maize varieties which could be utilized for further improvement in maize breeding.

Yield of chromosomally engineered durum wheat-Thinopyrum ponticum recombinant lines in a range of contrasting rain-fed environments

Introgressions of Thinopyrum ponticum 7AgL chromosome segments, spanning 23%, 28% and 40% of the distal end of durum wheat 7AL arm, were previously shown to contain multiple beneficial gene(s)/QTL for yield-related traits, in addition to effective disease resistance (Lr19, Sr25) and quality (Yp) genes. In the present study, durum wheat near isogenic recombinant lines (NIRLs), harbouring each of the three introgressions, were included for the first time in multi-location field trials, to evaluate general and environment-specific effects of the alien chromatin on 26 yield-related traits. Results from nine different trials across contrasting environments of Italy, Morocco and South Australia over four years revealed that the overall impact of 7AgL introgressions into the tetraploid wheat background did not incur, except in one environment, a major yield penalty. The effect of the three 7AgL segments on individual yield-contributing traits resulted in significant increases of biomass m−2 (+9%), spike number m−2 (+13%), grain number m−2 (+11%) and spikelet-1 (+8%), as well as a significant decrease in grain weight (−8%). When the separate NIRLs were analysed, each of the three 7AgL segments were associated with specific yield component variation. The effects of the 40%-long segment proved to be the most stably expressed across environments and involved significant increases of spike and grain number m−2 (13% and 15%, respectively), grain number spike-1 (10%) and spike fertility index (46%), though accompanied by a significant decrease in thousand grain weight (−23%). In spite of this trade-off between grain number and grain weight, their interplay was such that in four trials, including drier environments, a grain yield advantage was observed. This evidence, and comparison with the two other NIRLs, substantiates the hypothesized existence of major gene(s)/QTL for grain number in the most proximal 28–40% 7AgL region, exclusive to the 40%-long 7AgL introgression. The present study represents an important validation of the use of chromosomally engineered genetic stocks for durum wheat improvement, targeting not only disease resistance and quality traits but also relevant yield components.

Principal component analysis of early generation sorghum lines for yield-contributing traits and resistance to midge

ABSTRACT Sorghum (Sorghum bicolor L. Moench) is a staple food crop in Niger. Its production is constrained by sorghum midge (Stenodiplosis sorghicola Coquillett 1898) and by the use of low-yielding, local sorghum varieties. To improve sorghum productivity, farmers need high-yielding and midge-resistant sorghum cultivars. The objective of this research is to evaluate genetic diversity among sorghum inbred lines for yield, yield-contributing traits, and resistance to midge. Two-hundred and eighty-two lines (280 recombinant inbred lines plus two checks) were evaluated at two experimental sites in Niger. An alpha (0.1) lattice design with two replications was used to conduct the trial. Principal component analysis was used to determine the relationship between grain yield and resistance to midge. The first three principal components (PC) accounted for 56.22% of the total genotypic variation. Based on the similarity of traits within and between members of clusters, genotypes were divided into 18 clusters. Genetic variability was present for the traits under study in the tested germplasm. Hybridization of midge-resistant genotypes from different clusters should be able to yield new genotypes combining high yield and other desirable yield-contributing traits.

Modeling the Competitive Effect of Euphorbia dracunculoides and Astragalus sp. in Zero Input Rainfed Chickpea

ABSTRACT: Brown chickpea (Cicer arietinum L.) is one of the two chickpea types grown in Pakistan and other countries. The critical period for weed removal in a rainfed chickpea system is an important consideration in devising weed management strategies. Field experiments were conducted in the winter season of 2011 and 2012 to determine the extent of yield loss with different periods of weed crop competition. Seven weed crop competition periods (0, 45, 60, 75, 90, 105 and 160 days after sowing - DAS) were used to identify the critical period for weed removal in rainfed chickpea. Experimental plots were naturally infested with Euphorbia dracunculoides and Astragalus sp. in both years. Individual, composite density and dry weights of E. dracunculoides and Astragalussp. increased significantly with an increase in the competition period. However, yield and yield-contributing traits of chickpea significantly decreased with an increase in the competition period. Chickpea seed yield loss was 11-53% in different weed crop competition periods. Euphorbia dracunculoides and Astragalus sp. removed 39.9 and 36.9 kg ha-1 of N, 9.61 and 7.27 kg ha-1 of P and 38.3 and 36.9 kg ha-1 of K, respectively. Season long weed competition (160 days after sowing) resulted in 19.5% seed protein content compared with 24.5% seed protein content in weed-free chickpea. A Logistic equation was fitted to yield data in response to increasing periods of weed crop competition. The critical timing of weed removal at 5 and 10% acceptable yield losses were 26 and 39 DAS, respectively. The observed critical period suggests that in rainfed chickpea, a carefully timed weed removal could prevent grain yield losses.

Assessment of Ratooning Ability and Heterotic Effects for Yield and Yield Contributing Traits in Intraspecific Hybrids of Upland Cotton

The development of high yielding cotton hybrids is essential to meet the current cotton demands. On the other hand, the cotton ratooning allows to obtain maximum seed yields with early maturity of plant. Therefore, the present study was aimed to investigate the per se performance, ratooning ability and heterosis effects for yield and yield contributing traits in 28 novel hybrids through line x tester analysis by considering four varieties as lines and seven varieties as testers. Significant variability was observed for all investigated traits excluding the number of monopodial branches and boll weight traits in parents and their 28 hybrids. Among the parents, TSH 0499 and TSH 04/115 exhibited a fair performance for yield and yield contributing traits and SURABHI, TSH 0250 and VS 9-S11-1 expressed superior ratooning ability. Therefore, these parents have a potential to be exploited for the development of the efficient cotton hybrids. Among the tested F1 hybrids, TSH 0499 x TCH 1777, BGDS 1063 x TCH 1819, TSH 0499 x TCH 1819 and TSH 04/115 x SVPR 4 hybrids recorded superior performance for number of bolls, boll weight, lint index and seed cotton yield in first crop, respectively. The hybrids ARBC 19 x TSH 0250, TSH 0499 x SURABHI , TSH 0499 x TSH 0250 and TSH 0499 x TCH 1705-101 displayed good ratooning performance for number of bolls, boll weight, lint index and seed cotton yield, respectively. All the hybrids expressed a range of significantly positive and negative heterosis for tested traits. However, the observed negative heterosis for seed index is desirable since the hybrids produce more lint. The results of this study would give insights into the understanding of genetic variance present in the intra-hirsutum hybrids.

Estimation Heterosis and Combining Ability for Yield and Yield Contributing Traits in Two -Rowed Barley Using Line X Tester

Estimation Heterosis and Combining Ability for Yield and Yield Contributing Traits in Two -Rowed Barley Using Line X Tester

Studying Combining Ability and Heterosis in Different Cotton (Gossypium hirsutum L.) Genotypes for Yield and Yield Contributing Traits

Studying Combining Ability and Heterosis in Different Cotton (Gossypium hirsutum L.) Genotypes for Yield and Yield Contributing Traits

Genetic Variability and Its Implications on Early Generation Sorghum Lines Selection for Yield, Yield Contributing Traits, and Resistance to Sorghum Midge

Sorghum is the second most important cereal crop in Niger. The crop is grown in a wide range of ecological environments in the country. However, sorghum grain yield in Niger is limited by both abiotic and biotic constraints. Recombinant inbred lines derived from the cross of a local variety with a midge resistant variety and two local checks were evaluated during the 2015 rainy season across two planting dates in two environments in Niger. The objective was to investigate genetic variability for yield, yield related traits, and resistance to sorghum midge. High phenotypic coefficient of variation (PCV) versus genotypic coefficient of variation (GCV) was observed in both sites and planting dates. Across planting dates at both Konni and Maradi, grain yield, plant height, panicle weight, and midge damage had high heritability coupled with high estimates of genetic advance. At Konni, high genetic advance coupled with high heritability was detected for grain yield, plant height, panicle weight, and resistance to midge. There were similar results at Maradi for grain yield, plant height, and panicle weight. Therefore, selection might be successful for the above characters in their respective environments.

Micronutrient seed priming improves stand establishment, grain yield and biofortification of bread wheat

Agronomic biofortification by seed treatments is a convenient way to harvest improved yields of micronutrient-enriched grains. This 2-year field study was conducted to evaluate the effects of seed priming with zinc (Zn), boron (B) and manganese (Mn) alone and in combinations on stand establishment, grain yield and biofortification of bread wheat (Triticum aestivum L.). Seeds of wheat cv. Faisalabad-2008 were soaked in aerated solutions of 0.5 m Zn, 0.01 m B and 0.1 m Mn, alone and in different combinations, for 12 h. Seed priming with the micronutrients was quite effective in improving stand establishment, yield-contributing traits, grain yield, and straw and grain micronutrient contents during both years. Best stand establishment was achieved from seed priming with Zn+B, followed by seed priming with Zn+Mn. Grain yield improvement from different seed priming treatments was in the order Zn+B > Zn+Mn > Zn > B > Mn > Zn+B+Mn, with respective increases of 34%, 33%, 21%, 19%, 18% and 8% relative to untreated seeds. Seed priming with Zn, B and Mn alone and in combinations also improved the contents of the respective micronutrients in straw and grain. All seed priming treatments were economically profitable except Zn+B+Mn, which was not cost-effective. The highest benefit : cost ratio accrued from seed priming with Zn+B. In conclusion, seed priming with micronutrients was generally cost-effective in meeting the crop micronutrient requirements, and in improving crop stand, grain yield and grain micronutrient contents in bread wheat. Seed priming with Zn+B was the most effective in this regard.

Genetic Variability, Heritability and Diversity for Yield Contributing Traits in Reference Varieties of Wheat

Genetic variability study in 129 wheat varieties (80 bread and 49 durum wheat) revealed high magnitude of variability and high degree of heritability for majority of yield associated traits. Difference between the PCV and GCV was high for harvest index followed by number of grains per spike and grain yield/plant indicating the influence of environment on their expression. High magnitude of genotypic coefficient of variation (≥ 17.0%) was observed for spike length, plant height, grain yield/plant and flag leaf length, which indicates high degree of genetic variability and offers great scope for selection of these characters. High to moderate heritability coupled with high to moderate genetic advance as percentage of mean was exhibited for 7 traits viz., days to flowering, days to maturity, plant height, number of tillers/plant, biomass/plant, flag leaf length and 1000 grain weight, which indicated the predominance of additive gene action in the expression of these characters and very high possibility of improvement through selection for all these characters. Bread wheat varieties viz., CPAN 3004, GW 322, HI 617, HI 1500, DWR 39, DWR 195, GW 89, UP 2113, NP 700 and NP 771 and durum wheat varieties viz., A-28, HI 8381, MPO 215, HD 4530, HD 4672, NIDW 295, Raj 1555 and UAS 415 were found to be superior for grain yield and other traits along with being divergent from other lines, which can be utilized as donors for developing superior genotypes with high grain yield.

Reproductive, pathogenic and genotypic characterisation of five Meloidogyne graminicola populations from the Philippines on susceptible and resistant rice varieties

SummaryFive populations ofMeloidogyne graminicolaisolated from different rice-growing areas in the Philippines were characterised. The populations showed little phenotypic variability of second-stage juveniles and female perineal pattern. Differences in reproduction amongM. graminicolapopulations were not observed on mature resistantOryza glaberrimavarieties ‘TOG5674’, ‘TOG5675’, ‘RAM131’ and ‘CG14’, or on susceptibleO. sativavarieties ‘IR64’ and ‘UPLRi-5’. In all infected rice varieties, plant growth and yield-contributing traits showed no differences among the populations. A search onM. graminicolapopulations from the Philippines for single-nucleotide polymorphism on the sequences of Internal Transcribed Spacer (ITS) of rDNA genes and mtDNA indicated only few points of heteroplasmy. Nematode reproduction and disease induction of the fiveM. graminicolapopulations in the Philippines exerted the same level of aggressiveness and virulence. The absence of resistance-breaking populations ofM. graminicolais important for the maintenance of durability of resistance to this important rice pathogen.

Genetic variability and correlation studies for vegetative, reproductive and yield attributing traits in papaya

An experiment was carried out with 5 parent and 3 hybrid papaya genotypes to study the genetic variabilityand correlation between different yield attributing traits by evaluating 16 vegetative, reproductive, and fruit yieldcontributing traits during 2016–2017. The findings indicate that the maximum fruiting zone (129.8 cm) was in PS3 followed by PS 3 × P-7-9 (128 cm). The hybrid PS 3 × P-7-9 had maximum number of fruits per plant (44.67), minimum fruit weight (1020g) and maximum yield per plant (46.33 kg/plant) among the three hybrids evaluated. The phenotypic coefficient of variation (PCV) is higher than the genotypic coefficient of variation (GCV) for allthe traits studied. The genotypic variance and phenotypic variance were high for traits like leaf width, stemdiameter and fruit weight. Traits such as leaf length, petiole length, number of fruits per plant, fruit diameterand fruit yield exhibited higher value of GCV and PCV. Heritability for traits ranged from 53.83 to 99.49, of whichmajority of traits showed very high heritability, except some traits such as inflorescence size and fruit lengthwhich showed moderate heritability. Genetic advance (GA) was recorded highest for fruit length (179.13). Traitslike fruit yield, petiole length and leaf length exhibited high heritability accompanied by high to moderate geneticadvance indicating additive gene action, which suggest that selection may be effective for these traits. The trait, fruit yield was positively associated with plant height at flower initiation and maturity stage, stem diameter, daysto flowering, fruiting zone, number of fruits per plant and fruit diameter.

Genetic Analysis of Yield Contributing Traits in Lowland Rice Genotypes under Acidic Soils

Genetic Analysis of Yield Contributing Traits in Lowland Rice Genotypes under Acidic Soils

Impact of Sowing Interval on the Yield and Yield Contributing Traits of Sesame (Sesamum indicum L.) under the Tropical Circumstance

Abstract The experiment was conducted to study the impact of sowing interval on the yield and yield contributing traits of sesame (Sesamum indicum L.), under the tropical circumstance, during 2016, at the research area present near Faculty of Agriculture, Lasbela University of Agriculture, Water and Marine Science, Uthal, Balochistan. Experimental treatments were comprising three varieties of sesame, SV1 (TS-5), SV2 (TH-6) and SV3 (4002), and cultivated under different three sowing dates, at 15 days interval: S1 = 1st sowing (15 March 2016), S2 = 2nd sowing (1st April 2016) and S3 =3rd sowing (15 April 2016). The results of various observations, i.e. plant height at maturity (cm), 1000-seed weight (g), seed mass (t ha−1), yield index (%) rooting depth (cm) and root weight per plant was found to be significant both for the all the sowing dates and sesame genotypes. Non significant finding was observed in traits of biological yield per plant (g) and root-shoot ratio. Whereas interaction among all the treatment factors was non-significant. Maximum yield and yields contributing parameters was observed in S3 = 3rd sowing (15 April 2016) and sesame genotype SV1 (TS-5), followed by SV2 (TH-6), while minimum yield was noted in S3 = 3rd sowing (15 April 2016) and SV3 (4002) sesame genotypes. On the basis of the coastal agroclimatic condition of district Lasbela, it was concluded that maximum yield production was achieved from the sesame variety (TS-5), as compared to other two sesame (TH-6 and 4002) varieties. Sowing date of sesame at 15th April 2016 was more productive, as compared to the other sowing interval. Coastal climatic condition is feasible for sesame cultivation, especially for the sesame variety (TS-5).

Yield and Yield Contributing Traits of Cotton Genotypes as Affected by Sowing Dates

Yield and Yield Contributing Traits of Cotton Genotypes as Affected by Sowing Dates

Genetic Divergence Among Post-rainy Season-Grown Sorghum Local Landraces and Varieties for Morphological and Yield Traits

Post-rainy season-cultivated sorghum lines are local landraces, known for their grain quality and used exclusively for human consumption. Because of their importance, the present study was undertaken to estimate genetic diversity for morphological and yield-contributing traits at two locations. The ANOVA for days to flower, stem diameter, panicle width, yield per plant and 100 seed weight showed significant differences among 85 sorghum landraces and 15 popular varieties. Mean squares for all the traits were significantly affected by genotypes (G), environments (E) and G × E interaction. Relatively high broad-sense heritability was observed for grain yield at BARC, Mumbai (E1), and panicle length at ARS, Gulbarga (E2) locations, respectively. Significant positive correlations between panicle width and grain yield (0.23**) and between seed weight and grain yield (0.22**) were observed. Cluster analysis based on Euclidean distance grouped all the genotypes into five clusters with PC-6 emerging as a distinct variety. Promising landraces identified in this study would serve as genetic resources for recombination breeding.

English

A line x tester mating design involving sixteen white maize inbred lines as females and two testers as males generated thirty-two single crosses. These hybrids plus three checks were evaluated using a 5 x 7 alpha lattice design replicated twice at the University of Ghana, WACCI research farm during 2015/16 offseason using drip irrigation. The objective of the study was to: assign the tropical inbred lines into heterotic groups. Based on the SCA effect for grain yield, the lines were separated into two heterotic groups. The lines L1, L3, L4, L8, L11 and L14 belonged to tester group 1368, while L2, L5, L6, L7, L9, L10, L12, L13, L15 and L16 belonged to heterotic group of CML 444. This is useful for the development of hybrids and synthetic varieties. Thus, the information generated in the present study will be useful for breeders who want to improve yield and yield-contributing traits of maize. Key words: Hybrids, heterotic group, line x tester (LxT), maize, yield.

Validation of Seed Weight-Associated SSR Markers and Their Usefulness in Distinguishing Chickpea Genotypes According to Seed Size

Chickpea is an important cool-season grain legume. High-quality seed has the potential to attract premium prices. Hence, the breeding for desirable quality traits, including seed size and weight, is important. A set of 27 chickpea genotypes comprising 14 small and 13 large seeded, representing desi and Kabuli types, were used in the present study. A total of 43 SSR markers which were earlier reported to be associated with 100-seed weight and yield-contributing traits following QTL mapping in unrelated genetic background were used for validation purpose. Out of 43 SSR primers, 33 showed polymorphism amplifying 135 alleles. Neighbor joining-based analysis separated small- and large-seeded genotypes into two broad groups. These markers could distinguish small-seeded chickpea from that of large-seeded ones as well as desi types from that of Kabuli types, thereby validating all these QTL-linked markers in different genetic backgrounds. Fifteen of these primers also amplified 20 unique alleles in 13 chickpea genotypes and can be useful in molecular characterization and identification of specific genotype which has now become mandatory under Protection of Plant Varieties and Farmers Rights’ Act of India.

Association Studies of Yield Contributing and Physiological Traits on Yield in Mungbean (Vigna radiata (L.) Wilczeck) under Summer Condition

Association Studies of Yield Contributing and Physiological Traits on Yield in Mungbean (Vigna radiata (L.) Wilczeck) under Summer Condition

Line × Tester Analysis for Earliness Yield and Yield Contributing Traits in Gossypium hirsutum L.

The present study was carried out at Agriculture Research Institute (ARI) Tando Jam during 2016. The experimental material consisted of six lines viz., CRIS-134, Sindh-1, Sadori, Malmal, IR-901 and three testers; Bt-3701, Bt-121 and CIM-534.The crosses were made in line × tester mating design. F1 hybrids along with parents were sown in Randomized Complete Block Design with four replications in 2016. Seven yield and early maturing traits was recorded like, days to 1st flowering, days to 75% boll opening, plant height(cm), sympodial branches plant-1, bolls plant-1, seed cotton yield-1(g) and lint (%) for estimating of combining ability. The analysis of variance showed that genotypes, crosses, parents, parent vs crosses, lines, testers and line × tester were significant which demonstrated that genetic difference were present in genotypes for various yield and early maturing parameters. Among the lines, Sindh-1, CRIS-134 and testers, Bt-121 and Bt-3701 were best combiners and F1 hybrids like CRIS-134 × Bt-3701, Malmal × Bt-3701, CRIS-134 × Bt-121 were best combiners for all characters.