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Volume 6 Number 1 2012
CONTENTS AND ABSTRACTS
Omalsaad, Mohamad Osman (Malaysia), A. K. M. Aminul Islam (Bangladesh) Characterization of Roselle (Hibiscus sabdariffa L.) and Kenaf (Hibiscus cannabinus L.) Accessions from Different Origin Based on Morpho-agronomic Traits (pp 1-6)
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Original Research Paper: The evaluation of morpho-agronomic traits was carried to identify the genetic relationship between two species of Hibiscus, roselle (Hibiscus sabdariffa L.) and kenaf (Hibiscus cannabinus L.). Significant differences for morphological and agronomic characteristics were observed among roselle and kenaf accessions. The kenaf accessions showed better agronomic performance for most of the plant characteristics than roselle. Accession G4 had the tallest plants (213.0 cm) and number of branches/plant (24.83) among all accessions. ‘Noonsoon’ produced the highest stem diameter (8.61 cm) whereas ‘Khoken’ had the highest number of fruits/plant (226). Dendogram generated using morpho-agronomic characters were classified sixteen accessions into two main groups A and B. Five kenaf accessions included in group A whereas nine roselle accessions and two kenaf accessions were included in second group B. Roselle accessions were forming a group with a range of similarity coefficients of 0.5333 to 0.8780. ‘Bengkalis’ was close to roselle accessions although it was from different Hibiscus sp. ‘Noonsoon’ was very close to roselle accessions having a range of similarity coefficients of 0.5000 to 0.6326. Morphological characters would not be sufficient source for identification of relationship between roselle and kenaf varieties. In some cases, it was difficult to distinguish two species on the basis of morphological characters.
Ram C. Sharma (Uzbekistan), Alexey I. Morgounov (Turkey), Hans J. Braun (Mexico), Beyhan Akin, Mesut Keser, Yuksel Kaya (Turkey), Zakir Khalikulov (Uzbekistan), Maarten van Ginkel (Syria), Amor Yahyaoui (Mexico), Sanjaya Rajaram (Syria) Yield Stability Analysis of Winter Wheat Genotypes Targeted to Semi-Arid Environments in the International Winter Wheat Improvement Program (pp 7-13)
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Original Research Paper: Improved winter wheat (Triticum aestivum L.) cultivars for semi-arid environments in Central and West Asia are needed to increase wheat productivity. This study was conducted to determine the performance of winter wheat genotypes for semi-arid environments, analyze their stability, and identify superior genotypes that could be valuable for winter wheat improvement or varietal release. One hundred thirty three advanced breeding lines and four check cultivars were tested over a 6-year period (2005-2010). Grain yield stability and agronomic traits were analyzed. Many genotypes produced higher grain yield and were more stable than one or more of the checks in each year. By and large, different genotypes showed superior performance under low and high productive environments, demonstrating their specific adaptability. However, 11 out of 30 highest yielding genotypes were common both under low and high productive environments. This shows that while in general different sets of genetic materials are needed under strictly semi-arid and irrigated environments, a few lines targeted towards stressed conditions possess yield plasticity resulting in superior performance both under dryland and irrigated conditions.
Ayman Diab, Ayman Amin, Salwa Badr (Egypt), Jaime A. Teixeira da Silva (Japan), Pham Thanh Van (Japan/Vietnam), Bassem Abdelgawad, Sami Adawy, Reda Sammour (Egypt) Identification and Functional Validation of Expressed Sequence Tags (ESTs) Preferentially Expressed in Response to Drought Stress in Durum Wheat (pp 14-20)
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Original Research Paper: Drought is a major planetary stress problem that places greater limits on cereal productivity. Crop species belonging to the tribe Triticale represent the main foodstuff sources for humans. Because durum wheat (Triticum turgidum L.) shows better adaptation to semi-arid climates than bread wheat, itsgenome are likely to contain a pool of genes that are expressed for wide environmental adaptability. To investigate and understand the genetic response of drought tolerance in durum wheat, differentially expressed sequence tags (dESTs) were detected, characterized and cloned from durum wheat under different regimes of drought stress and the functions of some of these dESTs were determined. In this study, genes involved in drought stress at early stages of growth were profiled by a differential display technique from Egyptian durum wheat (Sohag 3). One, three, six, and 10 hours of drought stress were applied to produce 15 expressed cDNA fragments, which highlighted the genes that were expressed under drought stress, and which might help to understand the plant’s defense mechanism under drought conditions. This will also provide an opportunity to identify gene(s) for future use in transgenic research to enhance drought tolerance in wheat and other commercially important crops. The cloned dESTs could also be used as molecular markers for genetic and QTL mapping for wheat and other cereals under drought stress conditions.
Jamal-Ali Olfati, Habibollah Samizadeh, Gholam-Ali Peyvast, Babak Rabiei, S. Akbar Khodaparast (Iran) Relationship between Genetic Distance and Heterosis in Cucumber (pp 21-26)
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Original Research Paper: In heterosis, hybrids perform better than the parents for a collection of characteristics. Heterosis has been utilized in many crops, including cucurbits, to exploit dominance variance through the production of hybrids. For determine the relationship between heterosis and genetic distance sample seeds of 6 cucumber (Cucumis sativus L.) lines were received from Europe and Asia. All lines were crossed with a partial diallel test. The experiment was a randomized complete block design with 15 F1 hybrid and 6 parents and three replications. Factor analysis was performed using measured data. In related to the Eigen value we detected 8 factors and the specific combining ability (SCA) effects for the parents were estimated following Griffing’s (1956) model 2 and 4 for these factors. Cluster analysis indicated three branches in Ward’s tree. Using cluster analysis, information about the relationships among the investigated genotypes was obtained. Results showed that by increasing the genetic distance at first heterosis increased but when the genetic distance increased from special point by increasing of genetic distance heterosis decreased. So in hybrid seed production the breeders must be selected the lines with a moderate genetic distance.
Raja Shankar, Arjun Lal (India), Jaime A. Teixeira da Silva (Japan), Tukaram A. More (India) Diversity Analysis of Fleshy Leaf Type Amaranthus for Semi-arid Ecosystems (pp 27-33)
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Original Research Paper: The lack of fleshy leaf type varieties in Amaranthus is the major reason for poor consumer acceptance as the existing genotypes wilts within 2-3 h of harvest. To search for a fleshy leafy type, 28 accessions comprising A. tricolor, A. cruentus, A. hybridus and A. dubius were collected and examined for 22 descriptors based on morphological characters and nutritional values. There was significant variability in the gene pool, evident by a high variation as per cent of mean or coefficient of variation (CV). Principal component analysis revealed that plant height, number of branches/plant, internode length, number of leaves/plant, leaf length, leaf width, petiole length, node at which a flower appeared, plant weight and leaf weight exhibited 94% of the total variability. Hierarchical cluster analysis classified the accessions into 12 cluster groups at 0.78 Euclidean distances: clusters I, II, III and V were major clusters having 14, 2, 2 and 2 accessions, respectively. Yield/plot had a significant positive correlation with leaf length (r = 0.44), leaf width (r = 0.51), stem weight (r = 0.98), leaf weight (r = 0.94), number of leaves/plant and shoot weight (r = 0.98). Accession IC-469646 had fleshy, broad leaves with high yield potential coupled with higher Ca, Vitamin-C and Fe content.
Blessing C. Aruah, Michael I. Uguru (Nigeria), Benedict C. Oyiga (Germany) Genetic Variability and Inter-Relationship among some Nigerian Pumpkin Accessions (Cucurbita spp.) (pp 34-41)
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Original Research Paper: Ten Nigerian pumpkin accessions were evaluated during the 2007 and 2008 planting seasons to estimate the magnitude of genetic variability and the character association among some yield characters. The results revealed wide genetic variability among the accessions. The genotypic and heritabilty estimates were high in days to 50% emergence, days to 50% flowering, fruit diameter and number of seeds/fruit in both planting seasons. However, genotypic and heritability estimates were low in number of male and female flowers at both planting seasons. At both plantings, the number of seeds/fruit had a significant (P < 0.01) positive correlation with the number of male flowers/plant and fruit diameter. A significant positive correlation was also obtained between the number of female flowers and the number of fruits/plant in both planting seasons, an indication that both traits increased or decreased simultaneously. Thus, increasing the number of female flowers would favour fruiting in pumpkin. In both planting seasons, path analysis revealed that days to 50% flowering had the highest positive direct effect on fruit weight and also, had a high direct contribution to the fruit yield. The significant positive correlation between the weight of harvested fruits and fruit diameter in the 2007 planting season was due to the combination of the direct and indirect effects of fruit diameter to fruit yield. In 2008 planting, the number of female flowers recorded high positive direct effects on the weight of fruits/plant but its influence was nulified by the high negative indirect effects (-0.46) of number of fruits/plant. The results indicated that days to flowering, fruit diameter and number of seeds/fruit can be used as selection criteria to increase fruit yield in Nigerian pumpkins.
Yared Semahegn Belete, Sentayehu Alamerew Kebede, Adugna Wakjira Gemelal (Ethiopia) Heritability and Genetic Advance in Ethiopian Mustard (Brassica carinata A. Brun) (pp 42-46)
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Original Research Paper: Evaluation of locally adapted genotypes is helpful in endeavor of improvement of oilseed of Ethiopian mustard (Brassica carinata A. Brun). The present investigation was undertaken to evaluate the performance of different genotypes of Ethiopian mustard, and to estimate the heritability and genetic advance of agronomic traits of these genotypes. The experiment was laid out in simple lattice design at Holetta Research Center, Ethiopia. Wide ranges of mean values were observed for traits such as days to flowering (61-101), days to maturity (155-182), plant height (177-235 m), number of secondary branches per plant (5-25), number of pods per plant (123-279), number of seeds per pod (6-14), number of seeds per plant (3-11), seed yield per plot (334-1300 g), oil yield per plot (141-584 g) and 1000-seed weight (2.4-4.6 g). High genotypic and phenotypic coefficients of variation were shown in traits such as seed yield per plot and oil yield per plot. Low to high heritability values were recorded for the traits studied. High heritability values were recorded for traits such as days to flowering (79.3%), plant height (62.8%), 1000-seed weight (57.9%) and days to maturity (57.5%). Number of seeds per pod, seed yield per plot and oil yield per plot were found to have high genetic advance along with moderate heritability. Thirteen genotypes had days to maturity less than the grand mean as well as the standard checks which may be used for developing early maturing varieties. Traits which showed wide range of variations may serve for further breeding and selection. Employing breeding procedure such as pedigree method may be helpful for improvement of those traits which showed high genetic advance along with moderate heritability.
Raghuprakash R. Kastoori, Kiran Babu Talluri, Sivaramakrishnan Subramonian, Varaprasad S. Kodeboina, Someswara Rao Pandravada, Anuradha Ganta, Mani M. Khagendra (India) Isolation of Resistance Gene Candidates in Chilli and Use of Molecular Markers for Root Knot Nematode Resistance (pp 47-52)
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Original Research Paper: Chilli or hot pepper (Capsicum annuum L.), a major commercial vegetable crop of India is challenged with a number of pests and diseases and considerable economic damage, caused by root knot-nematode (RKN). Use of cultivars resistant to RKN would obviate the need for the use of pesticides. More than 40 resistant genes have been reported so far in various crops based on a candidate gene approach to address various biotic stresses. In the present study, isolation of these resistance gene candidates (RGCs) has been performed using a PCR-based approach involving degenerate primers designed based on the conserved nucleotide binding site (NBS) domains. Of the 41 clones sequenced, 9 NBS sequences with complete open reading frames (ORFs) had high similarity with the known resistance (R) genes, and are denoted as CaRGCs (Capsicum annuum resistant gene candidates). The presence of internal conserved motifs provided evidence that sequences isolated from chilli may belong to the NBS-LRR family. A cluster analysis based on the deduced amino acid sequence was carried out on chilli NBS-sequences, together with several analogous domains of known R genes, allowing chilli sequences to be classified into three major groups. The ratio of non-synonymous to synonymous nucleotide substitution (dN/dS) in the NBS domains of chilli RGCs ranged from 0.064 to 0.38 for the different classes, which suggests purifying selection. We report that the partial coding sequence CaRGC6, which shows similarity to a nematode resistant protein, could have a potential advantage in the development of a transgenic chilli provided the full length gene is isolated and characterized.
Thirupathi Reddy Medagam, Hari Babu Kadiyala, Ganesh Mutyala, Hameedunnisa Begum, Reddivenkatagari Subbararama Krishna Reddy (India) Exploitation of Heterosis for Growth, Earliness and Yield Attributes in Okra (Abelmoschus esculentus (L.) Moench) (pp 53-60)
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Original Research Paper: Heterotic studies of 45 single crosses derived from crossing 10 horticulturally superior, optimally diverse and nearly homozygous lines of okra (Abelmoschus esculentus (L.) Moench), namely P1(IC282248), P2(IC27826-A), P3(IC29119-B), P4(IC31398-A), P5(IC45732), P6(IC89819), P7(IC89976), P8(IC90107), P9(IC99716) and P10(IC111443) in a half diallel fashion over three seasons (early, mid and late kharif, 2009) revealed an appreciable amount of average heterosis and heterobeltiosis in a desirable direction in a good number of crosses for the majority of growth, earliness and yield attributes. Cross C4(P1×P5), displaying high negative heterosis over the standard check for days to 50% flowering (-4.24%) and first flowering and fruiting node (-13.22 %) is important to exploit heterosis for earliness in okra. The crosses with non-significant standard heterosis in any direction for total yield per plant C42(P7×P10), C31(P5×P6), C35(P5×P10), C25(P4×P5) and C17(P2×P10) and marketable yield per plant C42(P7×P10), C31(P5×P6), were statistically on par with the standard check in their mean performance and were as promising as that of the standard check under comparison (Mahyco Hybrid No. 10). Of the two comparable hybrids identified for both total yield and marketable yield/plant (C42 and C31), the F1 hybrid C42(P7×P10) also had good fruit quality, which can be exploited after further testing at different locations for commercial cultivation for the entire kharif season.
Muhammad Ilyas Khokhar (Pakistan), Jaime A. Teixeira da Silva (Japan) Heterosis for Improvement of Various Agronomic Traits in Bread Wheat (pp 61-64)
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Original Research Paper: Heterosis studies in 12 crosses of bread wheat involving nine varieties (Uqab-2000, Punjab-96, Inqilab-91, Shafaq-06-, Seher-06, Lasani-08, Achyuta, Oasis and AS-2002) and an advanced line (V-03094) were carried out at the Wheat Research Institute, Faisalabad. Highly significant genetic variability was present in the experimental material for the traits under study. Most of the crosses showed significant heterosis over mid- and better-parents for various characters. The Oasis/Punjab-96 cross depicted highly significant and the maximum heterosis and heterobeltiosis for grain yield/plant, spike length, number of spikelets/spike and flag leaf area. However, maximum 1000-grain weight and number of tillers/plant were produced from the cross V-03094/Uqab-2000. These crosses will be considered for finding transgressive segregants in advanced segregating generations for the evolution of wheat varieties with high yield potential.
Ali Qaid Ahmed Yahya Algabal, Narayanaswamy Papanna, Ajay B. C., Ahmed Eid (India) Studies on Genetic Parameters and Interrelationships for Pulp Yield and its Attributes in Tamarind (Tamarindus indica L.) (pp 65-69)
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Original Research Paper: Tamarind is an important multipurpose tree used mainly as a spice. In order to understand variation in 36 accessions, different variability parameters like genotypic coefficient of variance (GCV) and phenotypic coefficient of variance (PCV), heritability and genetic advance as per cent mean were estimated for pulp yield and its attributes. High PCV and GCV were recorded for vein weight and pulp weight. Pod weight, seed weight and pod length had high heritability coupled with high genetic advance. Pods (r = 0.384 and r = 0.394) and seed weight (r = 0.450 and r = 0.438) had a significant positive correlation at the genetic and phenotypic level, respectively and influenced pulp weight both directly and indirectly. Pod length, despite having a low correlation, had a high negative indirect effect on pulp weight. Hence, direct selection for pod weight and seed weight could be followed to increase pulp yield. In addition to the variability information on genetic traits, GCV, PCV, and genetic advance as per cent mean are much more essential as they are more reliable for effective selection. The PCV was higher than GCV for all the characters under study which suggests that these traits studied had low environment influence. However, in the present study, high heritability coupled with high per cent mean of genetic advance was observed for the characters viz. pod length, pod weight, shell weight, pulp weight and pod weight. Selection for these characters would be effective as they are more likely to be controlled by an additive gene effect.
Govindan Velu, Ivan Ortiz-Monasterio (Mexico) Variation in Grain Zinc and Iron Concentration in Wheat Germplasm of Diverse Origin (pp 70-72)
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Short Communication: Micronutrient malnutrition, resulting from dietary deficiency of important minerals such as zinc (Zn) and iron (Fe), is a widespread food-related health problem. In a recent initiative of CGIAR’s HarvestPlus challenge program is embarked upon to address this issue through the development of biofortified cultivars with elevated levels of these micronutrients in common wheat (Triticum aestivum L.). Genetic enhancement mainly depends on existence of genetic variability available in the gene pool. Hence, the magnitude of variability for grain Zn and Fe concentrations were studied in 600 wheat core-collection accessions of diverse origin. Grain Zn concentrations among the accessions ranged from 16.85 to 60.77 mg kg-1 and Fe concentrations ranged from 26.26 to 68.78 mg kg-1. The highest levels of Zn concentrations were observed in a Chinese spring bread wheat accessions “HONG DUAN MANG“ and highest Fe concentration was observed in a accession originated from Spain ‘ANDALUCIA 344‘. Top ranking accessions with high Zn and Fe concentrations are being evaluated for multi-locational testing to study the expression of these micronutrients in target countries, also these accessions are being used as potential donor for further germplasm improvement at International Maize and Wheat Improvement center (CIMMYT), Mexico. There was a highly significant and positive correlation between Zn and Fe concentrations (r=0.81; P<0.01), indicating simultaneous improvement of both of the micronutrients would be effective and high Fe and Zn sources identified in this study provide a valuable genetic resource for breeding cultivars with high Zn and Fe concentrations. |
