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July 2008

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Effect of genotype, explants, growth regulators and sugars on callus induction in cotton (Gossypium hirsutum L.)

Zouzou Michel 1, *Kouakou Tanoh Hilaire 2, Koné Mongomaké 2, Amani Nguessan Georges 3, Kouadio Yatty Justin 2

1 Université de Cocody, UFR Biosciences, Laboratoire de Physiologie Végétale,
22 BP 582 Abidjan 22, Côte d’Ivoire
2 Université d’Abobo-Adjamé, Laboratoire de Biologie et Amélioration des Productions
Végétales, UFR SN, 02 BP 801 Abidjan 02, Côte d’Ivoire
3 Université d’Abobo-Adjamé, UFR STA, Laboratoire de technologie alimentaire, 02 BP 801 Abidjan 02,
Côte d’Ivoire

*Corresponding author :
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Ten cotton (Gossypium hirsutum L.) genotypes were chosen for tissue culture. Callus initiation was genotype dependent, and R405-2000 has the best callogenesis response. Callus was induced from three media, the percentage of callus induction and dry weight of callus varied, but MS was the best callogenesis medium. It appeared that it was much easier to induce callus from hypocotyl than cotyledon or root explants. Induction callus of cotton was varied with hormone regimes. In effect, a proper combination of 2,4-dichlorophenoxyacetic acid (2,4-D) and kinetin (KIN) promoted the callus initiation. Glucose was the best sugar to promote the production of callus. However, the concentrations of glucose were critical to the induction of callus. The optimum glucose concentration for callus induction was 40 g/L. The best medium for the proliferation of callus was MS medium with 0.1 mg/l 2,4-D, 0.5 mg/l KIN and 4% glucose. An efficient protocol for the production of high frequency callus of cotton has been developed.

Callogenesis, Explant, Gossypium hirsutum L., Nutrient medium, Plant growth regulator, Sugar

Genetics of fibre quality traits in cotton (Gossypium hirsutum L.)

*Muhammad Amjad Ali, Iftikhar Ahmad Khan1, Shahid Iqbal Awan, Shiraz Ali and Shahid Niaz

Barani Agricultural Research Station, Fateh Jang, Pakistan.
Department of Plant Breeding & Genetics, University of Agriculture, Faisalabad, 38040, Pakistan

*Corresponding author’s email:
                                                                                                                                                             (PDF Link)
Five upland cotton varieties were crossed in a complete diallel mating system to assess the genetics of fibre length (FL), fibre strength (FS), fibre fineness (FF), fibre uniformity (FU) and fibre elongation (FE) utilizing Mather and Jinks approach. Differences were found to be significant (P<0.01) for all the characters. Adequacy tests revealed that data of all the characters were partially adequate for genetic interpretation except FE. Additive component (D) was significant in all the traits and was lower in magnitude than dominant components (H1 and H2) of variation for FS and FU which was firmly supported by the value of H1/D0.5. Dominant genes were in excess than recessive genes in the parents for all the traits except for FF. Asymmetrical distribution of dominant and recessive genes in parents for all characters was confirmed, and soundly sustained by the value of H2/4H1. The h2 value was insignificant for all the characters except FS. Moderately high narrow sense heritability (h2n.s) was exhibited by FF, FU and FE, while SL and FS possessed low heritability. Graphical representation demonstrated additive gene action for SL, FF, and FE whereas; FS and FU were controlled by overdominance effects. Full sib or half sib family selection, pedigree and progeny test would probably be necessary to achieve the genetic progress for SL, FF, and FE while hetrosis breeding could be fruitful for improvement of FS and FU.

Keywords: Gossypium hirsutum L., genetic effects, components of variation, fibre quality.

Efficacy of different herbicides over manual weeding in controlling weeds in transplanted rice

1*Mirza Hasanuzzaman, 1Md. Obaidul Islam, 2Md. Shafiuddin Bapari

Department of Agronomy, Sher-e-Bangla Agricultural University, Bangladesh
2Department of Agronomy, Bangladesh Agricultural University, Mymensingh, Bangladesh

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An experiment was conducted on transplanted Aman (monsoon) rice at the Sher-e-Bangla Agricultural University farm Dhaka (90033´ E longitude and 23077´ N latitude), Bangladesh during June-November, 2005. There were seven different weed control treatments viz. T1= Amchlor® 5G @ 15 kg ha-1 + IR5878® 50 WP @ 120 g ha-1, T2= Ronstar® 25EC @ 1.25 L ha-1 + IR5878® 50 WP @ 120 g ha-1, T3= IR5878® 50 WP @ 150 g ha-1, T4= IR5878® 50 WP @ 120 g ha-1, T5= Set-off® 20WG @ 50 g ha-1 + IR5878® 50 WP @ 120 g ha-1, T6= Two hand weeding and T7= Weedy check. There were 14 different weed species infested the field among which Panicum repens was the most important. Among the herbicides T2  was the most efficient with the lowest weed population and weed dry weight. The yield and the yield contributing characters (plant height, number of effective tillers per hill, panicle length and no. of filled grains) were influenced according to the effectiveness of the treatments, with T2 being the highest yielding herbicide treatment, reaching the yield level of the hand weeding treatments (T6). Maximum benefit-cost ratio with T2 suggested that this herbicidal treatment can be used as an alternative when labour is a limiting factor in producing transplant Aman rice.

transplanted rice, herbicide, weed control, yield, profitability

Physiological and biochemical behavior in soybean (Glycine max cv. Sambaiba) plants under water deficit

Allan Klynger da Silva Lobato, Cândido Ferreira de Oliveira Neto, Benedito Gomes dos Santos Filho, Roberto Cezar Lobo da Costa, Flávio José Rodrigues Cruz, Hadrielle Karina Borges Neves, Monick Jeane dos Santos Lopes

1Universidade Estadual de Maringá, Programa de Pós-graduação em Genética e Agronomia, Maringá, Paraná, Brazil.
2Universidade Federal Rural da Amazônia, Laboratório de Fisiologia Vegetal Avançada, Belém, Pará, Brazil

Corresponding author:
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The experiment had the aimed at evaluating the effects of the progressive water deficit, as well as investigating the physiological and biochemical behavior in Glycine max cv. Sambaiba submitted to water restriction during the vegetative phase. The parameters that were measured are the leaf relative water content, plant dry matter, proline, total soluble carbohydrate, sucrose, reducing carbohydrates, free amino acids and total soluble proteins. The experimental design carried out was at entirely randomized factorial scheme, with 2 water regimes (stress and control) and 4 evaluation points (0, 2, 4 and 6 days). There was decrease in the leaf relative water content in plants under water deficit, however the total soluble carbohydrates, sucrose and reducing carbohydrates were increased at 40, 205.0, 19.2%, respectively, besides the accumulation of proline and free amino acids at 67 and 388.1%, respectively. Significant changes were shown on leaf relative water content, total soluble carbohydrates, sucrose and reducing carbohydrates with 2 days under water stress, indicating that the carbon metabolism is quickly modified and utilized as reserve source and membrane protector during the water deficit. Besides of this, the increase in free amino acids level occurred due to protein breakdown as consequence of the stress submitted to plants, however significant changes were not observed on the proline levels until the 4th day of water restriction. This fact reveals the inefficient osmotic adjustment and as consequence the high sensitivity of this species under conditions of water restriction.

Glycine max, soybean, water deficit, carbon metabolism, nitrogen metabolism, carbohydrates, proteins

A preliminary study on the effects of ozone exposure on growth of the tomato seedlings

*N. Sudhakar, D. Nagendra-Prasad, N. Mohan and K. Murugesan

Centre for Advanced studies in Botany, University of Madras, Guindy campus, Chennai - 600 025, India.

*Corresponding author:
                                                                                                                                                           (PDF Link) 
A study was conducted to evaluate the consequence of application of ozone for a diminutive period repeatedly on tomato seedlings to enhance their biomassTo study the kinetics of these stress-induced growths in more detail we used short pulses (2 min) of ozone (O3) exposure at high concentrations as elicitor. The seedlings treated with different concentration of ozone (0.1, 0.2, 0.3, 0.4 ppm) are referred to as T1, T2, T3 and T4 seedlings respectively. The seedlings treated with ambient air are referred to as control seedlings. Among the treatments, T2 seedlings have a positive effect of an increased leaf area, enlarged shoot size and root length on biomass production than T1, T3, and T4 seedlings relative to control seedlings. Although T3 seedlings show enlarged shoot length; the root length and leaf area was reduced than T2 seedlings.  The T4 seedlings show greatly reduced root length, stunted shoot and shrunken leaf size than T1, T2 and T3 seedlings.
Hence, only the T2 concentration of ozone affords 33% enhanced dry weight and strict biomass allocation to leaves, shoot and rootFurther studies are needed to identify the mechanism of these preliminary conclusions.

biomass, Lycopersicon esculentum cv. PKM1, ozone, reactive oxygen species.

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