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Contextualization: pea is a legume with a high nutritional potential because it is a source of protein and is widely cultivated throughout the world. Knowledge gap: Even though the percentage of germination of pea seeds is high, this germination is uneven since most legumes have different degrees of dormancy, which generates plants of different sizes and with gaps in the phenological stages of the crop. Purpose: evaluate the effect of different doses of gibberellins [GAs] on the ger mination and growth of pea seeds, variety 'Santa Isabel'. Methodology: through a completely randomized design [DCA] with six treatments, which corresponded to the different doses of gibberellins applied [0, 200, 400, 600, 800 or 1000 mg L-1], every germination variable and subsequent growth of pea seedlings were evaluated. Results and conclusions: The application of GAs decreases the average germination time. The GAs generated seedlings with more height, but with thinner stems; while the seedlings from seeds without GAs were smaller, but with greater fresh and dry mass of leaves, and with greater aptitude for transplanting. The application of GAs in pea seeds did not affect the total dry and fresh mass of the pea seedlings, neither the MSR nor the MFR. The GAs promoted the redistribution of photo-assimilates by increasing the dry and fresh mass of stems at the expense of decreasing the dry and fresh mass of leaves and stipules. As the dose of gibberellins increased, the translocation of photo-assimilates from the seed to the stem specifically increased. [ABSTRACT FROM AUTHOR]

Copyright of Revista Foco (Interdisciplinary Studies Journal) is the property of Revista Foco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of BIOAGRO is the property of Revista BIOAGRO and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Agrobiotechnology seeks that biological molecules help to improve the soil, promote plant growth, generate defense mechanisms in plants, obtain better fruits and seeds, and maintain production for much longer. In this regard, plant hormones have been investigated in recent years, due to their chemical characteristics and potential use. These are expressed in all stages of the life cycle of plants, but their concentration depends on genetic, biotic and abiotic factors, which influence their activity. That is why they have been chemically synthesized and sources of microorganisms that are capable of producing them have been sought, in order to be able to obtain a greater quantity and availability of them. Advances in its production have led to the establishment of different techniques for its quantification and identification. The present review aims to update the knowledge and importance of these biological molecules with a promising use in different fields of agriculture. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of BIOAGRO is the property of Revista BIOAGRO and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Gibberellins control various aspects of plants growing and development, including seed germination, stem elongation, leaves expansion, flower and seed development. They are also involved in phase changes in some species, as from vegetative transition to reproductive. Most of these aspects seem to be regulated by DELLA proteins, which are negative regulators of the induced growth by GAs. The asynchronism in flowering processes of coffee and pineapple plants is recognized. This is also directly associated with the low quality of productions of both species. Studies that allow understanding this process are very important. This article shows a characterization in silico of supposed DELLA proteins in the database of CAFEST genome, gene bank of pineapple and GenBank to understand the role of DELLA proteins in the coffee and pineapple flowering processes. Structural similarity and expression profile in silico showed by probable DELLA genes in coffee corroborated the classification of DELLA proteins and suggest the presence of two of them in this specie. In pineapple, after an exhausted search, none of the bank genes proteins from this specie and the GenBank showed DELLA motifs in the four domains with structural functions related to the control of GAs. Nevertheless, in the future these analyses should be repeated due to the possibility that the corresponding sequences of these genes may not be present in the analyzed database. [ABSTRACT FROM AUTHOR]

Rice (Oryza sativa L.) is one of the most important crops in the world. For this reason it is necessary to know how plants respond to it and the possible modulation of their concentrations. The aim of this research was to evaluate through cDNA microarray the expression of expressed sequence tags obtained from the stem tissue in a variety of rice "Hangfeng" treated with applications of the phytohormone gibberellin for 36 hours. Gibibberellin is a hormone that controls several important aspects in the development of plants. Thus, to go deepen in knowledge about this crop genome, an analysis of 2535 expressed sequence tags (ESTs) was done using microarray technology. Plants were previously treated with gibberelen phytohormone at 36 hours and stem tissue samples were taken when plants had from five to six leaves to proceed with total ARN extraction (Trizol method). A total of 1129 ESTs was classified into 18 functional categories according to the requirements established by the Munich Information Center for Protein Sequences (MIPS). Unique transcripts were involved in metabolism (18.5%) and energy (16. 19%) for a total of 214 and 181 ESTs respectively. As microarray result, 10 ESTs were generated at the 36 hour-treatment with the phytohormone, and four of those ESTs (Tubulin beta-1 chain, Auxin-responsive protein IAA16, Actin-depolymerizing factor 5 and Xyloglucan endotransglucosylase) had never been reported before in Oryza sativa L. Array results were confirmed using real time PCR. [ABSTRACT FROM AUTHOR]

Copyright of Revista Chapingo Serie Horticultura is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Vegetable hormones are capable of controlling the reproductive development, from the flower differentiation until the last stages in the fruit development. In particular, the fruit set and development stage depends on the endogenous content of this substance, being possible to manipulate the beginning of the fruit development by external application of hormones. We have previously evaluated the fruit set and development process in tomato cultivation in greenhouse in response to the application of β-NOA and GA3 in fixed doses. Differential sensitivity was observed depending on the genotype and regulator type. The purpose of this work is to establish the optimum dose and moment for the application of β-NOA and GA3 as ways to improve the fruit set and development of parthenocarpic fruits. Regulator types β-NOA and GA3 in variable doses and application moments were considered as factors. Using unpollinated ovaries as an experimental system, it was possible to conclude that the application of 40 ppm of β-NOA at 7 days post antesis would offer the best advantages from a performance point of view and a lower physiologic impact, not altering the period of fruit development. [ABSTRACT FROM AUTHOR]

The present study was conducted in San Clemente, Chile (35°33′ S lat; 71°24′ W long), during the 1996-1997 and 1997-1998 growing seasons, and was aimed to determine the approximate induction, and flower differentiation dates on apples (Malus domestica Borkh.) cvs. Royal Gala, Fuji, Red Chief and Braeburn. Induction date was determined by applying gibberellin GA4+7 (100 mg kg-1) and weekly manual thinning, from full bloom up to 70 days after full bloom (DDPF). Flower differentiation was evaluated by collection and tissue dissection of floral buds, between December 1996 and June 1997. The period of maximum sensitivity of flower induction could only be determined by gibberellin application, which was found between 7 and 21 DDPF for R. Gala, R. Chief and Braeburn. Trials related with flower induction had high variation coefficients (22 to 57%), probably due to the rootstock (seedling), low G4+7 concentration or inefficient thinning, and mainly due to high tree vigor, as shown by shoot length, 50 cm on average, which is almost twice of that recommended in other foreign literature. Nevertheless, data suggest that this event occurred about 14 and to 21 DDPF for GA4+7 experiments, and around 35 days DDPF for thinning experiments. Flower differentiation was determined on January 6, 1997 (100 DDPF) in cv. Fuji, R. Chief and Braeburn, and January 20 (114 DDPF) in cv. R. Gala. [ABSTRACT FROM AUTHOR]

Pectimorf, a new Cuban bioregulator whose active principle is a mixture of oligosacarides of pectic origin, having the capacity to induce and develop rooting, to stimulate callus growth and remarkably increase the development and vigour of vitroplants in different cultures, is a promising alternative in crop biotechnology. Therefore, the objective of this work is to determine the effect of single and combined Pectimorf with GA3 and IAA on the composition of sugarcane artificial seed capsule. The work was made with somatic embryos obtained in calluses from segments of the most internal leaf of sugarcane plants, CP52-43 variety, planted under field conditions with nine months of age. Artificial endosperm became rich with Pectimorf (10 mg·L-1), that was combined with GA3 (0 and 2.0 mg·L-1) and IAA (0 and 0.5 mg·L-1) and a control treatment without hormones. Results showed a synergic effect of Pectimorf with IAA, which increased in the percentage of capsule germination, without reaction in the oligosaccharide interaction with gibberellin. When Pectimorf was applied as a single one, although it increased the number of plants, it was in detriment of the quality of them; the size, number of leaves and length decreased significantly and at the final evaluation, these capsules presented a high number of deformed plants that was not possible to evaluate. [ABSTRACT FROM AUTHOR]

The process of fruit set and development in tomato can be naturally induced by pollination or parthenocarpy and artificially by hormonal application; this response is variable according to type and dose of the hormone, moment of application and cultivar involved. The purpose of this work was to evaluate the capacity of auxins and gibberellins to induce the parthenocarpic development in genotypes of undetermined growth. The considered factors were type of regulator -AG3 and β-NOA- in set dose, moment of application -0, 5, 12, 19, 26 dpa-, and genotype -Rutgers, Fortaleza F1 and Colt 45-. The best responses regarding percentage of fructification and fresh weight are obtained with β-NOA in comparison with AG3. Considering all the analyzed factors, only the application of β-NOA to 5 dpa allowed to obtain the percentages of fruit set and final size of fruits similar to the ones obtained by autopollination. The period of sensitivity and the final size of fruits presented interaction with the genotype variables, moment of application and type of regulator. It was also observed that AG3 caused a scarce placental development and ovule absence while β-NOA induced a placenta and ovule development similar to the one in fruits obtained by autopollination. [ABSTRACT FROM AUTHOR]