International Journal of Plant Breeding and Genetics

International Journal of Plant Breeding and Genetics ISSN 5756-2145 Vol.  2 (4) pp. 154-160, April, 2015. © International Scholars Journals

Full Length Research Paper

Assessment of indigenous Arabica espresso genotypes accross over diverse situations

 *Tirunesh E. Bekele, Kenennisa Bikila and Abebe F. Isreal

Department of Breeding, Genetics, and Plant Molecular Biology, School of Biological Sciences, University of Gondar, Gondar, Ethiopia.

E-mail: [email protected] 

Accepted 09 March, 2015

Abstract 

Evaluation of 30 Arabica coffee genotypes was carried out at four different locations in south-western Ethiopia to identify genotypes that exhibits stable performance across wide environments. The analyses of variances revealed that yield differences among genotypes were highly significant at all locations in both seasons except at Jimma during the second season. The interaction was also highly significant. Six genotypes: 8211, 808, 8219, 75187B, 8143 and 8213 exhibited higher overall mean yield that ranged from 1217 to 1633 kg of clean coffee per hectare at the first two bearings. Such mean yield is very high as climax yield in Arabica coffee is attained starting from the fourth bearing stage. However, only three of these genotypes: 8213, 8143 and 75187B exhibited superior performance consistently at all locations irrespective of the interaction. The result of the trials is considered as one remarkable success in the history of Arabica coffee research as identifying genotype that exhibits stable performance across wide environments has long been a major challenge and in practicable for decades.

Key words: Agro-ecologies, Arabica coffee, environments, indigenous, genotypes.

International Journal of Plant Breeding and Genetics ISSN 5756-2145 Vol.  2 (3) pp. 138-153, March, 2015. © International Scholars Journals

Review

Customizing rice plants for manageable yield through ideotype rearing and physiological interventions

*Alshay E. Kapoor, Kareena Roshan and Mahatma V. Khan

Department of Breeding, Genetics, and Plant Molecular Biology, School of Biological Sciences, University of Delhi, New Delhi, India.

Accepted 26 February, 2014

Abstract 

The success of yield-improvement programmes hinges on the accurate selection of parents from which to generate superior breeding populations, and the selection of high-yielding genotypes from early-segregating generations. Development of the ideotype concept has focused the attention of plant physiologists and breeders on the identification of simple morphological characters which influence physiological processes determining yield. A major advantage in breeding for ideotype is that genes for certain characters can be easily introgressed from the related species with aid of biotechnological interventions. Characters such as leaf inclination and leaf shape are often simply inherited and can greatly influence crop canopy structure and radiation interception. Such characters could be rapidly modified by selection to increase crop photosynthesis and yield. This review provides integrated information on these relationships and gives plant breeders a blueprint of the characteristics of high-yielding cultivars of rice in specified environments.

Key words: Ideotype, physiological traits, sustainable yield, rice, new plant type.

International Journal of Plant Breeding and Genetics ISSN 5756-2145 Vol.  2 (3) pp. 127-137, March, 2015. © International Scholars Journals

Review

A report on traditional and atomic rearing methodologies for enhancing fiber quality attributes in cotton

*Ryan Drake, Jim Gosling E Seth and Myers Mitchell

 Department of Breeding, Genetics, and Plant Molecular Biology, School of Biological Sciences, University of Mumbai, Mumbai, India.

E-mail: [email protected] 

Accepted 21 February, 2014

Abstract 

The cultivated Gossypium spp. represents the most important, natural fibre crop in the world. India is the only country cultivating all the four cultivated species of cotton. Among the Gossypium spp., Gossypium hirsutum is the most cultivated species in many countries. Breeding for high cotton yield is still the primary goal of cotton breeding programs, but improving fibre quality has become increasingly important. The enhancement of fibre quality traits like fibre length, strength, and fibre fineness is an essential requirement for the modern textile industry. G. hirsutum is characterized by its high lint yield while Gossypium barbadense has good fibre quality. Through a conventional breeding strategy, introgression of useful alleles for fibre quality from wild species and G. barbadense to G. hirsutum will be the effective way to improve the fibre quality traits. The identification of the stable quantitative trailt loci (QTLs) affecting fiber traits across different generations will be very helpful in molecular marker-assisted selection to improve fiber quality of cotton cultivars. In this review, we present an overview of the genetics and conventional and molecular breeding techniques that have been used to increase the favorable fibre quality traits in cotton.

Key words: Cotton, fibre quality traits, simple sequence repeat (SSR), restricted fragment length polymorphism (RFLP), amplified fragment length polymorphism (AFLP), quantitative trait loci (QTLs).

International Journal of Plant Breeding and Genetics ISSN 5756-2145 Vol.  2 (3) pp. 120-126, March, 2015.  © International Scholars Journals

Full Length Research Paper

Hereditary proof of formative segments of parthenocarpy in Apomictic MUSA species

*Eguoko Patrick, Edoja Samson and Oniovosa Vincent

Department of Breeding, Genetics, and Plant Molecular Biology, School of Biological Sciences, University of Benin, Edo state, Nigeria.

E-mail: [email protected]

Accepted 18 February, 2015

Abstract 

Apomixis and parthenocarpy are broadly botanically defined as embryo and seed, and fruit development respectively, in the absence of fertilization. The objectives of this study were to genetically elucidate the development of apomictic seed and parthenocarpic fruit development in MUSA. Borneo and Calcutta 4 plants were vegetatively propagated and were assayed in replicates of 2 and 6, respectively at Onne and Ibadan, Nigerian locations. Each mother and ratoon was assayed over 2 flowering cycles, resulting in a total of 16 inflorescences analyzed. Pollination barrier procedures were performed involving bagging of the inflorescences, isolating them from natural pollinators. Scoring for apomixis was based on seed-set in isolated (bagged) inflorescences without pollination. Parthenocarpy was determined by seedless pulp development in open pollinated or as artificial pollination by Calcutta 4, using standard MUSA crossing procedures. Floral and fruit developmental traits indicated that Borneo was monoecious, comprising traits of apomixis and vegetative parthenocarpy. Borneo × Calcutta 4 cross, a P1-lacking, P2 and P3 modelled MUSA, suggests that Borneo may be genetically modelled to comprise P1 but lack P2 and/or P3. Such modifier genes appear to correlate with rates of genome by environment dependent seed development regimes and if not synchronized with fruit development regimes, results in dehiscence, death of developing fruit, and non-parthenocarpic expression.

Key words: Apomixis, banana, parthenocarpy, pollination, genotype, environment, Musa, modelling, genetics, Nigeria.

International Journal of Plant Breeding and Genetics ISSN 5756-2145 Vol.  2 (3) pp. 111-119, March, 2015.  © International Scholars Journals

Review

Quality pyramiding-An expansive range procedure for creating durable stress resistance in yields

 *Satyajit Akshay, Kishore shadid and Aishwarya Chopra

Department of Breeding, Genetics, and Plant Molecular Biology, School of Biological Sciences, Himachal Pradesh University, Shimla, India.

Email: [email protected]

Accepted 10 February, 2015

Abstract 

The development of molecular genetics and associated technology like MAS has led to the emergence of a new field in plant breeding-Gene pyramiding. Pyramiding entails stacking multiple genes leading to the simultaneous expression of more than one gene in a variety to develop durable resistance expression. Gene pyramiding is gaining considerable importance as it would improve the efficiency of plant breeding leading to the development of genetic stocks and precise development of broad spectrum resistance capabilities. The success of gene pyramiding depends upon several critical factors, including the number of genes to be transferred, the distance between the target genes and flanking markers, the number of genotype selected in each breeding generation, the nature of germplasm etc. Innovative tools such as DNA chips, micro arrays, SNPs are making rapid strides, aiming towards assessing the gene functions through genome wide experimental approaches. The power and efficiency of genotyping are expected to improve in the coming decades. The present review discusses the design parameters in a gene pyramiding scheme, potential application of gene pyramiding in crop plant improvement, and the prospect and challenges in integrating MAS based gene pyramiding with conventional plant breeding programmes.

Key words: Gene pyramiding, marker-assisted selection, durable resistance.

International Journal of Plant Breeding and Genetics ISSN 5756-2145 Vol.  2 (3) pp. 105-110, March, 2015. © International Scholars Journals

Full Length Research Paper

Genetic variation and heritability of yield and related traits in promising rice genotypes (Oryza sativa L.)

*Ferdinand Corazon, Emilio Pacquiao and Aguinaldo E. V

Department of Breeding, Genetics, and Plant Molecular Biology, School of Biological Sciences, University of the Philippines Manila, Ermita, Philippines.

Email: [email protected]

Accepted 05 February, 2015

Abstract 

A study was conducted during 2008 to 2009 in 12 environments in Nigeria, Benin Republic and Togo to evaluate genetic variation and heritability of yield and related traits in 48 rice genotypes. The experiments were laid out in a randomized complete block design (RCBD) with three replications. Genotypes differed significantly at p > 0.001 for all the traits studied, which implies that the genotypes contain adequate genetic variability. Phenotypic coefficients of variation (PCV) were higher than genotypic coefficients of variation (GCV) in all the characters across the 12 environments. High heritability estimates were obtained for days to flowering (91.37), days to maturity (86.86), plant height at maturity, number of tiller per meter square, panicle shattering, panicle threshability, panicle per meter and panicle length (72.21) suggesting that the traits are primarily under genetic control. High estimates of heritability, GCV and genetic advance (GA) observed for grain yield is an indication that selection for grain yield could be achieved through phenotypic performance. Furthermore, high estimates of heritability, GA and GCV recorded in these characters could be explained by additive gene action. Low estimates of heritability, GCV and GA recorded for grain yield and number of grains per panicle could be due to non-additive gene effect suggesting that these traits were less responsive to specific environment influences. Grain yield recorded highly significant positive correlation with panicle length (0.28), leaf width (0.40), grain length (0.30), number of panicles per meter square (0.19) and1000-grain weight (0.17). It correlated negatively with basal leaf sheath coloration (-0.33) and grain width (-0.20) in the 12 environments. The current study indicated that more number of tillers, panicles per meter square, long panicles, high number of primary and secondary branch panicles and large 1000-grain weight are important yield related traits and could be used for selection in rice breeding programs.

Key words: Correlation coefficients, heritability, phenotypic coefficients, rice, variability, yield components.