Genetics of Coastal Habituation: How Recombinant Inbred Lines Respond to Saline Environments | Chapter 10 | Agricultural Sciences: Techniques and Innovations Vol. 6

 

Background: Among all abiotic stresses, salinity is the second most widespread soil problem in rice-growing countries of the world after drought, which continues due to climate change and poor irrigation practices. Rice is highly sensitive to salinity, particularly at the seedling and reproductive stages. Identifying rice genotypes tolerating salinity both at the seedling and at reproductive stages that maintain stable yield in coastal saline soils requires an understanding of genetic variability and trait relationships in terms of direct and indirect effects to develop salt-tolerant rice varieties.

 

Aim: The aim of this study is to assess phenotypic performance and to estimate genetic variability for salt tolerance in both the seedling and reproductive stages of rice under coastal saline soils.

 

Methodology: The present study was conducted at the natural coastal saline soils of Acharya N. G Ranga Agricultural University (ANGRAU)- Agricultural Research Station (ARS), Machilipatnam, during Kharif (June to November) 2024. A field experiment was carried out to evaluate Recombinant Inbred lines (RILs) derived from the cross MCM 109/BRR 0119 for salt tolerance in an Alpha-lattice design. Here, 150 RILs at F5 generation were studied at pH 8.4, and EC 7.2 dSm-1 and data on yield and salinity traits were collected. Salt tolerance was evaluated at the seedling and reproductive stages using the standard evaluation system (SES), with scores from 1 (highly tolerant) to 9 (highly susceptible) based on growth, leaf symptoms, and spikelet sterility. Statistical analysis was performed using PBIB.test, GCV, PCV, heritability and GA as per cent of the mean were drawn from the variability package of R software.

 

Results: The analysis of variance (ANOVA) for 12 characters attributed significant differences among 150 RILs studied under salinity (P<0.01). The traits ear bearing tillers hill-1, salinity scoring at reproductive stage, shoot Na+/K+ ratio at harvesting stage, and grain yield per plant (g) exhibited high estimates of GCV, PCV, heritability and genetic advance as per cent of the mean, suggesting additive gene action. While the traits plant survival (%), plant height (cm), panicle length (cm), number of filled grains per panicle, spikelet fertility % and hundred grain weight (g) exhibited moderate PCV and GCV values with high heritability and genetic advance, indicating substantial genetic variability for effective selection.

 

Conclusion: Selecting RILs based on variability traits results in the development of salt-tolerant, high-yielding varieties suitable for coastal saline soils. RILs F5 112 and F5 248 can be released as high-yielding saline-tolerant varieties after evaluation in salinity trials and multi-location trials, whereas RILs F5 122 and F5 202 can be registered as genetic stocks for highly tolerant coastal saline conditions.

 

 

Author(s) Details

Vinutna Vinnakota
Department of Genetics and Plant Breeding, Agricultural College, Bapatla, Andhra Pradesh, India.

 

Girija Rani M
ANGRAU-RARS, Maruteru, West Godavari, India.

 

Nagendra Rao K
ANGRAU-ARS, Machilipatnam, Krishna, India.

 

Suneetha K
ICAR-IIRR, Rajendranagar, Hyderabad, India.

 

Ravi Babu M
ANGRAU-RARS, Anakapalle, Visakhapatnam, India.

 

Please see the link:- https://doi.org/10.9734/bpi/asti/v6/6807

Investigating Transgressive Segregation to Improve Yield in F2 Segregants of Sesame (Sesamum indicum L.): A Comprehensive Study | Chapter 9 | Current Research Progress in Agricultural Sciences Vol. 10

Sesamum (Sesamum indicum L.), one of the most ancient oil crops, has been referred to as the ‘queen of oilseeds’ by virtue of its high-quality oil. The experiment involved the F2 generation of three superior crosses of sesame: Thilak X Ayali 1, Thilathara X Ayali 2 and Thilak X Ayali 5, grown in a Compact Family Block Design. A total of 200 plants were grown with a spacing of 30 x 25 cm, and observations were recorded on yield-related characters. Biometric observations were recorded for nine characters viz, days to first flowering, number of primary branches, number of capsules per plant, capsule length (cm), capsule width (cm), number of seeds per capsule, days to maturity, plant height (cm) and seed yield per plant (g). The data were subjected to analysis of variance (ANOVA) and various genetic parameters were worked out using GRAPES software, version 1.1.0. Significant variation was found among most traits, except for capsule length, capsule width, number of seeds per capsule and the number of primary branches. Maximum coefficient of variation was recorded for number of capsules per plant (41.091) followed by seed yield per plant (40.163). The least coefficient of variation was recorded for capsule length (6.58) closely followed by the number of seeds per capsule (6.774). The cross Thilathara X Ayali 2 exhibited a high frequency of transgressive segregants for multiple traits, particularly for seed yield per plant, making it highly promising for further breeding efforts. Plant height had the highest mean and range, showing considerable potential for selection. CV analysis revealed high variability for traits like the number of capsules per plant and seed yield per plant. In contrast, low variability and high stability were observed for traits like capsule length, number of seeds per capsule and days to maturity. Higher PCV and GCV were recorded for traits like days to first flowering, number of capsules per plant, and seed yield per plant, showing substantial genetic and environmental influences. Moderate PCV and GCV were found for plant height and days to maturity, while traits like capsule length, number of seeds per capsule, and capsule width had the lowest PCV and GCV, indicating limited genetic variation. Days to first flowering and days to maturity showed high heritability combined with high genetic advance, suggesting the preponderance of additive gene action and are ideal for simple selection. Traits like capsule length, capsule width, and number of seeds per capsule showed low heritability and genetic advance, making them less ideal for selection. The cross, Thilathara X Ayali 2 should be prioritized in future generations to recover desirable segregants, especially for economically important traits like seed yield. In conclusion, it has been found that while certain traits are more influenced by genetic factors and suitable for selection, others are heavily impacted by environmental variability.

 

Author (s) Details

 

Greeshma Ravi
Department of Genetics and Plant Breeding, College of Agriculture, Vellayani, Thiruvananthapuram, 695 522, India.

 

Lovely B.
Department of Genetics and Plant Breeding, College of Agriculture, Vellayani, Thiruvananthapuram, 695 522, India.

 

Seeja G.
Department of Genetics and Plant Breeding, College of Agriculture, Vellayani, Thiruvananthapuram, 695 522, India.

 

Susha S Thara
Department of Plant Pathology, College of Agriculture, Vellayani, Thiruvananthapuram, 695 522, India.

 

Ninitha Nath C.
Department of Genetics and Plant Breeding, College of Agriculture, Vellayani, Thiruvananthapuram, 695 522, India.

 

Amritha K.B.
Department of Genetics and Plant Breeding, College of Agriculture, Vellayani, Thiruvananthapuram, 695 522, India.

 

Please see the book here:- https://doi.org/10.9734/bpi/crpas/v10/4908

 

Studies on Genetic Variability and Screening of Yellow Vein Mosaic Virus (YVMV) Resistance in Mutant Lines of Blackgram (Vigna mungo L. Hepper) under Field Condition | Chapter 2 | Contemporary Research and Perspectives in Biological Science Vol. 11

Background: A breeding program requires that a gene pool be made more genetically variable. In order to increase variability and find desirable recombinants, hybridisation and mutation techniques are used in tandem. The most important disease affecting and decreasing blackgram yield is yellow mosaic disease, which is caused by the Mungbean Yellow Mosaic Virus (MYMV). Blackgram crop land is being used for other cereal crop cultivation since resistant cultivars are not readily available. Breeding with these resistant cultivars is an eco-friendly and efficient way to manage MYMV in urdbean production.

Aim: The aim of the study is to assess the genetic variability and yellow vein mosaic virus (YVMV) resistance in mutant lines of blackgram (Vigna mungo L. hepper) under field condition.

Methods: In Agricultural and Horticultural Research Station, Bavikere a field experiment conducted at Kharif 2022 utilising 90 F4 M3 laid out in an Augmented design. For the summer of 2023, 30 F5 M4 were selected from the first season and laid out in an RCBD design based on seed yield, disease index, and incidence. These lines were produced by hybridising Rashmi and PU31, then treating F2 seeds at IIHR in Bangalore with gamma irradiation (20kr). Statistical analysis was performed on the data of traits means recorded on 15 selected plants for yield and its attributing traits using WINDOWSTAT version 9.2 software and R software.

Results: This study showed significant differences for most of the characteristics. The number of clusters per plant, number of pods per cluster, number of pod length, number of seeds per pod, and seed yield all showed high PCV, GCV, broad sense heritability, and genetic advancement as a percentage of mean for the first season. In terms of the number of branches per plant, number of clusters per plant, number of pods per cluster, number of pods per plant, and number of seeds per pod, high broad sense heritability with genetic advancement, moderate PCV, and GCV were showed for the second season. Estimated high PCV values suggest greater population variability in trait seed yield per plant, but the narrow range between GCV and PCV suggests that environmental influences on trait expression are less significant. The plants that exhibited the least percentage disease index and resistant reaction to YVMV were BLM 9, BLM 20, BLM 29, BLM 44, BLM 51, and BLM 58 in the first season, and BLM 30 and BLM 51 in the second.

Conclusion: This research suggests that additional crop improvement can be achieved with using these resistant high yielding mutant lines.

 

Author (s) Details

 

N. Nagamani
Department of Genetics and Plant Breeding, ZAHRS, Navile, Shivamogga, Keladi Shivvappa Nayaka University of Agricultural and Horticultural Sciences, Shivamogga, Karnataka-577204, India.

S. K. Shashikala
Department of Genetics and Plant Breeding, ZAHRS, Navile, Shivamogga, Keladi Shivvappa Nayaka University of Agricultural and Horticultural Sciences, Shivamogga, Karnataka-577204, India.

 

B. Manjunatha
Keladi Shivvappa Nayaka University of Agricultural and Horticultural Sciences, Shivamogga, Karnataka-577204, India.

 

N. Sadashiv
Department of Plantation, Spices and Aromatic Crops and Station Head, AHRS, Bavikere, Shivamogga, Karnataka-577204, India.

 

T. N. Usha
Department of Seed Technology, Directorate of Research, Keladi Shivvappa Nayaka University of Agricultural and Horticultural Sciences, Iruvakki, Shivamogga, Karnataka-577412, India.

 

Please see the book here:- https://doi.org/10.9734/bpi/crpbs/v11/4882

Characterization, Breeding and Selection of Rice Germplasm Panels Adapted to Low Soil Phosphorous and Nitrogen Environments in Kenya: An Advanced Study | Chapter 7 | Current Research Progress in Agricultural Sciences Vol. 8

Rice breeding efforts in Kenya have slowly been taking place to develop locally adapted high-yielding varieties with desirable eating qualities. Soil nitrogen (N) and phosphorus (P) deficiencies are among the major constraints constrictive to rice productivity globally, especially in resource-poor farming systems which were traditionally self-sustaining through slash and burn. There is therefore need to develop rice genotypes with enhanced root architecture that help them tolerate low soil N and P conditions. This work aimed at developing rice genotypes with enhanced tolerance to low N and P conditions through targeted breeding approaches that include hybridization, evaluations and recent works on rice research space. A diverse panel of rice germplasm obtained from CIAT Colombia as accessions and breeds for rainfed conditions were screened under controlled and field conditions to identify traits associated with nutrient use efficiency and generate information in this discipline. A total of 389 accessions and a local cultivar Duorado precoce were evaluated in a simple 30 × 13 alpha lattice design with two replications under four soil experimental environments (N⁻P⁻, no N or P application, N⁻P⁺, P applied, N⁺P⁻, N applied and N⁺P⁺, both N and P applied) at the rate of 60 kg P and 90 kg N ha^-1. Data was recorded on Days to heading, anthesis and maturity (days), P and N tolerance, plant height (cm), above ground biomass (g), number of panicles (absolute numbers per ten plants), days to maturity (days), 1000 grain weight (g), and grain yield (kg ha^-1). The genotypes and environments were highly significant for all the traits studied. The degree of genetic determination (H²) ranged from 6.8% for P tolerance to 36.5% for above ground biomass. The phenotypic coefficient of variation of genotypes ranged from 14.3% for days to maturity to 159.7% for top biomass. The genetic advance (GA) ranged from 0.2 for phosphorous tolerance to 1080.5 for grain yield, while the genetic advance expressed as a percent of the mean was 5.7% for days to maturity and 87.9% for top biomass. The top biomass seems to be a highly heritable trait and simple phenotypic selection is possible. The ten characters studied had wide variability under the four environments with days to maturity ranging from 188 for genotype ARCCU1Fa1-L4P3-HB under N⁺P⁺ to 177 for genotype CT16333(1)-CA-1-M under N⁻P⁻ condition. The highest yielding genotype was CT16328-CA-18-M under N⁻P⁻ with 5916 kg ha^-1. The germplasm showed variability for low soil N and P adaptation, and hence improvement was possible to take advantage of the vast unexploited both rainfed lowland and upland environments for increased rice productivity to meet food-feed and nutritional households and national security in Kenya. There was high variability among the genotypes to warrant rice improvement for yield. Field trials conducted at AfricaRice research fields in Senegal have revealed significant yield improvements in the newly developed lines under nutrient deficient, toxic elements and problem soil environmental conditions. This study underscores the potential of breeding for nutrient-efficient rice varieties as a sustainable economic solution that reduces the need for fertilizers used to enhance productivity in nutrient-poor soils, contributing to food-feed and nutritional security in sub-Saharan Africa.

 

Author (s) Details

Kimani J. M
Food Crops and Natural Resource Management Department, Kenya Agricultural and Livestock Research Organization, Industrial Crops Research Institute, P.O. Box 16-80109, Mtwapa, Kenya.

 

Sang Bok Lee
Korea-Africa Food and Agriculture Cooperation Initiative, Africa Rice Training Center, Saint louis Africa Rice (Saint-Louis Senegal) Ndiaye, B.P. 96, Saint-Louis, Senegal.

 

Kang Kyung – HO
Korea-Africa Food and Agriculture Cooperation Initiative, Africa Rice Training Center, Saint louis Africa Rice (Saint-Louis Senegal) Ndiaye, B.P. 96, Saint-Louis, Senegal.

 

Phoebe Anyango Sikuku
Department of Botany, School of Physical and Biological Sciences, Maseno University, P.O. Box Private Bag, Maseno, Kenya.

 

Emily Waringa Gichuhi
Kenya Agricultural and Livestock Research Organization, Industrial Crops Research Centre, P.O BOX 298-10300, Mwea, Kerugoya, Kenya.

 

Mutiga Samuel Kilonzo
International Maize and Wheat Improvement Center (CIMMYT) ICRAF House, United Nations Avenue – Gigiri, PO Box 1041-00621, Nairobi, Kenya.

 

David Mwongera Thuranira
Kenya Agricultural and Livestock Research Organization, Horticultural Research Institute, P.O BOX 220-01000, Thika, Kenya.

 

Clotilda Nekesa Ondiko
Food Crops and Natural Resource Management Department, Kenya Agricultural and Livestock Research Organization, Industrial Crops Research Institute, P.O. Box 16-80109, Mtwapa, Kenya.

 

Lusike Wasilwa
Kenya Agricultural and Livestock Research Organisation, Post Office: P.O.Box 57811, City Square, NAIROBI, 00200, Kenya Kaptagat Rd, Loresho Nairobi, Kenya.

 

John Kirao Kalume
Food Crops and Natural Resource Management Department, Kenya Agricultural and Livestock Research Organization, Industrial Crops Research Institute, P.O. Box 16-80109, Mtwapa, Kenya.

 

Tongoona P.
African Centre for Crop Improvement, University of Kwa Zulu Natal, Private Bag X01, Scottsville 3209, Republic of South Africa.

 

Derera J.
African Centre for Crop Improvement, University of Kwa Zulu Natal, Private Bag X01, Scottsville 3209, Republic of South Africa and International Institute of Tropical Agriculture (IITA), PMB 5320, Oyo Road, Ibadan 200001, Oyo State, Nigeria.

 

 

Please see the book here:- https://doi.org/10.9734/bpi/crpas/v8/4081

Genetic Diversity of Gloriosa superba Mutants | Chapter 4 | Research Advances and Challenges in Agricultural Sciences Vol. 8

 

The mutation breeding to assess character association, direct and indirect influence of characters on seed yield in the induced mutants of Glory lily and to assess the genetic variation among mutants by ISSR profile was carried out. The analysis of variance indicated significant differences among the treatments for most of the traits. Estimates of phenotypic coefficient of variation for the selected traits in VM2 generation were in general slightly higher than the genotypic coefficient of variation indicating the influence of environmental factors on these traits. High heritability and genetic advance as per cent of mean were recorded for most of the characters under the study indicating a better scope for further selection. Differential patterns resulted in ISSR analysis indicating the polymorphism created by induced mutagenesis, creating scope for the selection of desirable mutants in G. superba.

 

Author(s)details:-

 

Anandhi, S.
Department of Floriculture and Landscape Architecture, SRM College of Agricultural Sciences, SRM Institute of Science and Technology, Chengalpattu 603 203, Tamil Nadu, India.

 

Kanimozhi, C.
Department of Floriculture and Landscape Architecture, SRM College of Agricultural Sciences, SRM Institute of Science and Technology, Chengalpattu 603 203, Tamil Nadu, India.

 

Rajamani, K.
Department of Floriculture and Landscape Architecture, SRM College of Agricultural Sciences, SRM Institute of Science and Technology, Chengalpattu 603 203, Tamil Nadu, India.

 

Please See the book here :- https://doi.org/10.9734/bpi/racas/v8/3866G

Genetic Variability and Heritability in Diverse Accessions of Wild Noni (Morinda tomentosa Heyne ex Roth) in North Gujarat, India | Chapter 1 | Innovations in Biological Science Vol. 1

 The present study aims to provide valuable insights for the development of effective breeding strategies and the conservation of this important medicinal plant species. Genetic variability and heritability for morphological and phytochemical attributes were studied in Morinda tomentosa. The experimental material for the present investigation comprised 31 diverse accessions of wild Noni (Morinda tomentosa Heyne ex Roth) collected from forest areas of Panchmahals, Kheda, and Dantiwada during year, 2007-08. The magnitude of genotypic coefficient of variation was higher for all but number of seeds per fruit, flavonol content in leaf, number of branches per plant, flavonol content in fruit, fruit length, total soluble sugar, plant height, ascorbic acid content in fruit and fruit width indicating lesser role of environment in the expression of the traits. The broad sense heritability was higher for all but fruit width indicating explicit realization of heritable variance and thereby offering abundant chances of improvement in those characters by simple selection. Genetic advance is the ultimate objective of interest for a breeder. The genetic advance increases with increase in genetic variance. The heritability in broad sense as such also has little significance as it includes both additive and epistatic gene effects. The increased estimates of genetic advance with high heritability for fruit, leaf, and carotenoid content suggested that additive gene action had a role in the expression of these traits, further supporting the idea that phenotypic selection based on these features would be more successful.

Author(s) Details:

A. H. Rathod,
Department of Genetics and Plant Breeding, SD Agricultural University, Sardarkrushinagar, India.

S. Acharya,
Centre of Excellence for Research on Wheat, SDAU, Vijapur, India.

A. K. Singh,
Central Horticultural Experiment Station, Vejalpur, India.

Please see the link here: https://stm.bookpi.org/IBS-V1/article/view/14010

Studies on Correlation and Path Analysis in Medium Duration Rice Varieties of Andhra Pradesh, India | Chapter 6 | Emerging Issues in Agricultural Sciences Vol. 2

 The present study was attended to investigate the correlation and way analysis in twenty-five medium event (120-125 day) rice types (Oryza sativa L.). Rice (Oryza sativa L) is a critical necessary cereal crop that feeds more than half of the planet's population. The personality association of yield attributing characteristics revealed a important positive relationship 'tween plant height, 1000 children weight, and panicle length and seed yield per hectare. As a result, selecting for these traits can advance yield. In the current study, a high genetic cooperative of variation was noticed for number of seed/panicle, along with extreme heritability and genetic advance, displaying that there is room for bettering of the trait through natural selection. Following panicle length, 1000 source weight had defeater in competition positive direct effect on yield, according to a course coefficient study. The characters 1000 seed pressure and panicle length had a extreme direct effect as well as a positive partnership. Therefore, choosing these figures could result in an bettering in yield and yield components.

Author(s) Details:

N. K. Gayathri,
Acharya N. G. Ranga Agricultural University, Regional Agricultural Research Station, Nandyal, Kurnool, Andhra Pradesh, India.

Y. Padmalatha,
Agricultural Research Station, Garikapadu, Guntur, India.

Please see the link here: https://stm.bookpi.org/EIAS-V2/article/view/10044

Determination of Variability, Heritability, Genetic Advance and Their Interrelationships in Rabi Sorghum (Sorghum bicolor L. Moench) for Various Yield and Yield Contributing Traits under Drought Conditions | Chapter 1 | Current Topics in Agricultural Sciences Vol. 8

Studying the genetic variability characteristics is important for the efficient selection of crop species. Any breeding programme for crop improvement must have desired variation present, as well as a certain degree of heritable variation. As a result, every breeding effort for crop improvement is strongly reliant on genetic diversity, heritability, and genetic advancement. At the Sorghum Research Station, V.N.M.K.V., Parbhani, the genetic variability research for yield and yield contributing factors in 37 genotypes of rabi sorghum with three checks, M 35-1, Phule Suchitra, and CSV-22-R, was conducted during rabi 2019. To estimate the genetic variability for quantitative characteristics, the treatments were examined, and data for 11 traits were collected using a randomised block design with three replications. The discovery of extremely significant genotype differences reveals a substantial degree of variability in all 11 characteristics examined. Greater estimates of phenotypic coefficients of variation are obtained, and these estimates are of lower size, when phenotypic coefficients of variation are compared to genotypic coefficients of variation. Among the forty genotypes examined, VJV 107, VJV 106, PEC 30, RSV 1921, RSV 1945, and RSV 1984 were considered the superior genotypes since they outperformed the others. The goal of the current study was to calculate the genetic variability for quantitative characteristics.

Author(s) Details:

Kesoju Ravali,
VNMKV, Parbhani - 431 402 (M.S.), India.

J. E. Jahagirdar,
VNMKV, Parbhani - 431 402 (M.S.), India.

Please see the link here: https://stm.bookpi.org/CTAS-V8/article/view/7250

Assessment of Genetic Variability in Mid-altitude Sesame (Sesamum indicum L.) Collection of Ethiopia | Chapter 5 | Cutting-edge Research in Agricultural Sciences Vol. 8

 The aim of this study was to evaluate the genetic variability and character association in 81 Ethiopian mid-altitude sesame accessions based on important agronomic traits.

The study was conducted using a 9 x 9 Simple Lattice Design (SLD) with two replications.

Melkassa Agricultural Research Centre Ethiopia, during the major cropping seasons of July through December 2011.

Methodology: Using SAS 9.2 statistical software, the data on 14 quantitative traits were analysed for phenotypic and genotypic coefficients of variances, heritability and genetic advance, correlation coefficient, path coefficient analysis, principal component analysis, and divergence analysis based on Mahalanobis statistics to evaluate the pattern and extent of variation among 81 mid-altitudinal individuals. For all traits tested, analysis of variance showed major differences between genotypes. Many of the traits tested had less than 50% heritability. Most yield-related traits had moderate heritability and moderate to high genetic advance, suggesting that these traits are regulated by both additive and non-additive genes. The number of capsules, biomass yield, harvest index, and 1000 seed weight all showed a strong positive relationship with seed yield. Number of capsules, biomass yield, days to maturity, and harvest index had the greatest positive direct impact on seed yield, indicating that these traits can be used to boost the primary trait by selection. The genotypes were divided into seven groups based on divergence analysis using Mahalanobis statistics. The geographical distribution of genotypes was not taken into account. Cluster V and VII had the greatest inter-cluster gap, so genotypes from these two clusters could be used as parents in a hybridization programme to produce promising recombinants. Conclusion: There was ample genetic variability in the germplasm lines for seed yield and its components. Clustering was not linked to geographical distribution; rather, genotypes were clustered primarily based on morphological differences. The highest contributors to genetic divergence were seed yield, biomass/plant, harvest index, and number of capsules. These traits may be used in a sesame improvement programme to boost yield.

Author (s) Details

Mohammed Abate
Department of Plant Science, College of Dry-land Agriculture, Samara University, Afar, Ethiopia.

Firew Mekbib
Department of Plant Science, Haramaya University, College of AES, Dire Dawa, Ethiopia.

Amsalu Ayana
Integrated Seed Sector Development Ethiopia Program, Addis Ababa, Ethiopia.

Mandefro Nigussie
Ethiopian Institute of Agricultural Research, Addis Ababa, Ethiopia.

View Book :- https://stm.bookpi.org/CRAS-V8/article/view/787

Study on the Assessment of Genetic Variability Estimates of Selected Traits in Irish Potato Mutants| Chapter 6 | Current Strategies in Biotechnology and Bioresource Technology Vol. 3

 Objectives: Knowledge of genetic parameters of traits, such as heritabilities and genetic correlations, is important for an effective potato breeding strategy, hence the need to test genetic variability estimates of yield-related traits in Irish potato mutants Study Design: There was no replication of mutant minitubers at M1V1 generation because each does not maintain the same genetic minituber. The tubers were repeated in alpha lattice design 3 times in the generation of M1V2 and M1V3. Location and Period of Study: Irradiation was conducted at IAEA / FAO Seibersdorf Plant Genetics and Breeding Laboratories (PGBL), Vienna, Austria. The mutant microtubers (consisting of Asante, Mpya and Sherekea) were transported to Eldoret University, Kenya, for establishment between April 2015 and March 2017 following mutation induction. Methodology: A total of 30 tubers were dispatched to irradiate each of the three potatoes. Irradiation of in vitro nodal cuttings (without leaf) followed by in vitro shoot propagation and irradiation of in vitro nodal cuttings (with leaf) followed by direct in vitro micro-tuber development have been produced in two in-vitro radio-sensitivity tests involving different tissues. A total of 570 mutant microtubers (Asante 230, Mpya 160, Sherekea 180) were produced from the three potato varieties after mutation induction and were transported to Kenya to be formed at the University of Eldoret. In the greenhouse, the M1V1 microtubers were created, while the M1V2 and M1V3 mutant generations were planted in the research field at the University of Eldoret. Results: It revealed that in Mpya and Sherekea mutants, the highest positive heritability percentage (H2) estimates were 81.51 percent and 87.7 percent respectively in plant height. Conclusion: High heritability estimates of tuber numbers indicate that induced mutation has been effective in the production of new potato genotypes that will be used in future breeding programmes. The present study indicates that different genetic variability estimates were shown by the potato mutants. It was found that the number of tubers within the mutant populations exhibited high estimates of heritability. The induced mutation succeeded in producing new genotypes of potatoes that could be used in potential breeding programmes.

Author(s) Details

Dr. Emmy Chepkoech

School of Agriculture and Biotechnology, University of Eldoret, P.O.Box 1125-30100, Eldoret, Kenya.

Stephen Kimno
School of Agriculture and Biotechnology, University of Eldoret, P.O.Box 1125-30100, Eldoret, Kenya.

Miriam G. Kinyua
School of Agriculture and Biotechnology, University of Eldoret, P.O.Box 1125-30100, Eldoret, Kenya.

Oliver Kiplagat
School of Agriculture and Biotechnology, University of Eldoret, P.O.Box 1125-30100, Eldoret, Kenya.

Julius Ochuodho
School of Agriculture and Biotechnology, University of Eldoret, P.O.Box 1125-30100, Eldoret, Kenya.

Leah Boit
School of Agriculture and Biotechnology, University of Eldoret, P.O.Box 1125-30100, Eldoret, Kenya.
View Book :- https://bp.bookpi.org/index.php/bpi/catalog/book/306

Experiment on the Genetic Variation and Path Coefficient Analysis of Introgressed Maize Inbred Lines for Economic Traits | Chapter 16 | Research and Development in Agricultural Sciences Vol. 3

 Aims: To evaluate introgressed maize inbred lines and respective donor inbred lines for selected

economic traits and adaptability.
Study Design: Field evaluation was carried out in this study.
Place and Duration of Study: The experimental material comprised 123 inbred lines: 76
introgressed inbred lines that combined temperate and tropical germplasm. These inbred lines were
selected from three distinct environments (Rattray Anorld Research Station and Kadoma in Zimbabwe
and Ukulinga Research Centre in South Africa) to form three sets of introgressed inbred lines and
were considered as test genotypes. There was also a set of 26 temperate inbred lines, including the
inbred donor line that was used as a set of positive control inbred lines adapted to the South Africa
warm temperate environment. Additionally, a set of 21 tropical inbred lines was included as negative
control maize inbred lines from Zimbabwe tropical germplasm. The evaluation experiment was carried
out at Rattray Anorld Research Station (RARS), Kadoma Research Centre (KRC), Cedara Research
Station (CRS) and Ukulinga Research Stations (UKRS) in Zimbabwe and South Africa in 2012-13
summer season.
Methodology: Augmented alpha lattice experimental design was used to evaluate a total of 123
inbred lines that were randomly assigned into six blocks, in each block, ten test entries were randomly
assigned to plots within each block, and two common tropical control lines (SC21 and SC19; repeated
checks) were also randomly assigned in each block.
Results: Genetic variation was significant (P < 0.05) for all the major economic traits among inbred
lines within and across sets. Heritability estimates ranged from low (0.21%) to high (91%) for stalk
lodging and silking days, respectively. Comparison of means of inbred lines sets illustrated that
environmental effect had an influence on grain yield of introgressed lines. Grain yield and ear
prolificacy performance across sets also illustrated that introgression of temperate germplasm in
tropical elite inbred lines was effective. Spearman’s rank correlation analysis on grain yield and ear
prolificacy highlighted the correlation between selection environments. Correlation among traits
demonstrated that grain yield had significant (P < 0.05) positive correlation with plant and ear aspects,
plant height, root and stalk lodging, ear prolificacy and grain moisture content at harvest. Generally,
indirect effects of secondary traits on the grain yield potential of inbred lines were negligible.
Conclusion: From the results, introgressed inbred lines has a significant genetic variation that can be
explored to select inbred lines that have desired economic traits that enhance adaptability in South
Africa warm temperate environment. Traits such as plant and ear height, root and stalk lodging, ear
prolificacy and grain moisture content at harvest can be used to select for high grain yielding inbred
lines directly. Indirect secondary traits (plant height and ear prolificacy) can be emphasised during
introgression of temperate germplasm in tropical elite inbred lines .

Author (s) Details

Dr. L. Musundire
Seed Co. International Ltd., Potchefstroom, South Africa.

J. Derera
Seed Co. International Ltd., Potchefstroom, South Africa.

Dr. S. Dari
Crop Science Department, Faculty of Agriculture, University of Zimbabwe, Harare, Zimbabwe.

Professor P. Tongoona
West African Centre for Crop Improvement, University of Ghana, Ghana.

View Book :- http://bp.bookpi.org/index.php/bpi/catalog/book/266