Development and fruit yield of strawberry plants as affected by crown diameter and plantlet growing period

The objective of this work was to evaluate the influence of crown diameter and growing period of runner tips in 128 cell-trays on growth and yield of strawberry in the field. Treatments consisted of three classes of runner tip crown diameters, between 2.0 to 3.9 mm; 4.0 to 5.5 mm and 5.6 to 7.0 mm, respectively, and four growing periods in trays, 24; 39; 54 and 69 days, respectively. Higher shoot dry mass of transplants at planting and earlier yield of plants in the field were obtained in transplants grown for 69 days in trays. Larger runner tips lead to more vigorous transplants at planting and plants with higher vegetative growth in the field, with minor impact on yield. Increasing the growing time of runner tips in trays improved early fruit yield and decreased plant vegetative growth in the field.

Identification of plantlet genetic origin in polyembryonic mango (Mangifera indica, L.) cv. Rosinha seeds using RAPD markers

Mango can be propagated by seeds or by grafting. For commercial purpose, grafting is the most appropriate method because it maintains the genetic characters from the propagated variety. To obtain grafted mango it is important to use polyembryonic varieties as rootstock since they produce a zygotic and many nucellar plantlets. The nucellar plantlets maintain the genetics of the mother-plant thus, are preferred for grafting since they supposedly give more uniformity to the orchard. In general, nurserymen use the most vigorous plantelet to graft, believing that they are nucellar. But, orchard disuniformities on height and yield are very common among mango trees of commercial orchards in Northeast region. The objective of this paper was to identify the genetical origin of plantlets from polyembryonic seeds of Rosinha variety using Random Amplified Polymorphic DNA (RAPD) markers. Moreover, the position of the zygotic embryo and the percentage of the vigorous zygotic and nucellar plantlets was also determined. It was obtained an elevated taxa of vigorous zygotic plantlets which possibly explains the disuniformity on height of trees at commercial mango orchards.

Production of yacon plantlet (Polymnia sonchifolia poep. et endl.) in different organic fertilization

The work was carried out in nursery of the Agronomical Science College (ASC) UNESP-Botucatu, in period from September 21(st) to October 31(st) 2000. The propagation material (rhizophores) was obtained from plants, which were cultivated in the area of ASC. The rhizophores were selected according to their vigor and size. Healthy rhizophores were chosen between 15 and 25 g, which were treated with benomil (0,6%, 10 minutes). As a basic commercial substratum Solomix((R)) was used with mixing cattle manure and chicken manure in the following proportions: T1- pure substratum; T2 - substratum + cattle manure (1:1), T3- substratum + cattle manure (2:1); T4- substratum + chicken manure (4:1). The yacon rhizophores presented good shoots in all substrata with exception of T4. For all parameters no significant difference between the pure commercial substratum and its mixture with cattle manure were observed; however, the addition the chicken manure in the studied proportions revealed harmful effect on the survival and development of the plantlets. The results indicated, that the viability of smaller size rhizophores was higher as the size conventionally used in Brazil (60 to 80 g).

Restoration of Cymodocea nodosa (Uchria) Ascherson seagrass prairies through seed propagation. Germination in vitro, plantlet acclimation and transplanting to natural meadows.

[EN] The seagrass Cymodocea nodosa (Ucria) Ascherson is the most abundant seagrass species in the Canary Islands (Spain), where it forms dense submerged, ecologically relevant communities as stable and protected habitats. As with other seagrasses, concern has arisen due to a decline in the number and extension of the communities as the result of adverse activities in coastal areas. Seed germination and planting are assumed as cost-effective method for restoration. In the frame of the restoration of natural populations of Cymodocea nodosa, pilot experiences not tested so far in the Canary Islands have been carried out to developed in vitro techniques to produce viable seedlings and its transference to the natural environment.

EFFECT OF BAP, NAA AND GA3, EITHER ALONE OR IN COMBINATION, ON MERISTEM CULTURE AND PLANTLET ESTABLISHMENT IN SWEET POTATO (CV BRONDAL)

In Zimbabwe, the average sweet potato yield (6 t/ha) is relatively low when compared to Asian counterparts (17 t/ha). These low crop yields have been blamed on weevil infestations and viral infections which account for 60-90% of sweet potato yield losses in Africa. Meristem tip culture, a Centre for Potato Improvement (CIP) initiated tissue culture technique, has been widely used to eradicate viruses from clonally propagated crops and has been noted to be one of the instrumental techniques that helped China to increase sweet potato yields. In an effort to adopt the meristem tip culture technique for the production of virus-free planting material of a local sweet potato (cv Brondal), a study was conducted to evaluate the effect of Benzylamino purine (BAP), 1-Naphthaleneacetic acid (NAA) and Gibberellic acid (GA3) (either alone or in combination) on cultured Brondal meristems. The different hormonal treatments were assessed on the following parameters: plantlet regenerative capacity, multiple plantlet production, shoot height, average leaf number per shoot and average node number per shoot, ten weeks after meristem culture. All treatments containing a combination of BAP (1 mg-L) and GA3 (at either 5 mg-L, 10 mg-L, or 20 mg-L) had a significantly (p<0.01) higher plantlet regenerative capacity of 33-66% when compared to other treatment combinations. Only treatments, 10 mg-L GA3 + 1 mg-L BAP and 20 mg-L GA3 + 1 mg-L BAP were capable of inducing multiple plantlet formation, producing an average of three plantlets/meristem and two plantlets/meristem respectively. Overall, treatment 10 mg-L GA3 + 1 mg-L BAP gave rise to significantly (p<0.01) taller shoots (20 mm) compared to the rest of the treatments used. For average leaf number per shoot, all GA3 treatments (5 mg-L, 10 mg-L, or 20 mg-L) supplemented with 1 mg-L BAP gave significantly (p<0.01) higher numbers of leaves (six leaves/shoot) than the rest of the treatments. Treatments 10 mg-L GA3 + 1 mg-L BAP and 20 mg-L GA3 + 1 mg-L BAP gave rise to the highest number of nodes per shoot, producing an average of three nodes per shoot. In sharp contrast to treatments containing a combination of BAP and GA3, all treatments containing a combination of BAP and NAA performed poorly in all parameters tested for plant regeneration of Brondal sweet potato variety. In conclusion, the best hormonal treatment for culturing Brondal meristems proved to be 10 mg-L GA3 + 1 mg-L BAP.

pH do meio de cultivo e crescimento de plântulas de ginseng brasileiro cultivadas in vitro

O presente trabalho objetivou avaliar o efeito do pH do meio de cultivo sobre alguns parâmetros de crescimento da Pfaffia glomerata (Spreng.) Pedersen cultivada in vitro, bem como checar se o crescimento dos explantes altera o pH do meio ao longo do período de cultivo. Foram testados quatro tratamentos constituídos de distintos valores de pH (3,7; 5,0; 6,0 e 7,5) do meio de cultivo. O pH do meio de cultivo foi ajustado antes da inclusão do agar (6g L-1 - Merck) e da autoclavagem. Como fonte de explantes foram utilizadas segmentos nodais de plantas previamente estabelecidas in vitro em meio MS. Dos nove aos 15 dias após a inoculação (DAI) dos segmentos nodais, verificou-se maior número de raízes em pH 6,0 e o menor no pH 7,5. Aos 35 DAI, o comprimento da maior brotação e o número total de segmentos nodais por planta foram maiores em torno de pH 6,0. Aos 35 DAI, observou-se menor crescimento em biomassa de raízes em pH 3,7. Já a parte aérea apresentou menor biomassa em pH 7,5. Aos 35 DAI, a produção de matéria fresca e seca total da plântula foi maior em pH próximo a 6,0. Concluiu-se que valores de pH do meio de cultivo próximos a 6,0, ajustados antes da autoclavagem, são ideais para o crescimento da P. glomerata cultivada in vitro. Também se verificou que o crescimento da plântula modificou significativamente o pH do meio de cultivo.

Callus induction and plant regeneration from broccoli (Brassica oleracea var. italica) for transformation

We evaluated the efficiency of callus induction and plantlet regeneration from hypocotyl explants of broccoli (Brassica oleracea var. italica). The cultivars were ‘Marathon’, ‘Greenbelt’, and ‘Shogun’. Transformation success was not affected by the presence of tobacco feeder-cell layers on the culture media. The frequency of shoot regeneration was greater from 10-d-old hypocotyls than from 14-d-old hypocotyls. Both ‘Marathon’ and ‘Greenbelt’ had higher potentials for tissue regeneration than did ‘Shogun’. We found that for transformation selection, the optimum concentration was either 50 mg/L kanamycin or 100 mg/L genetkin.

Introducció experimental a la biotecnologia amb clavellina: cultiu in vitro

Treball de recerca realitzat per una alumna d'ensenyament secundari i guardonat amb un Premi CIRIT per fomentar l'esperit científic del Jovent l'any 2009. Es tracta d’una recerca experimental en la que s’han assajat vuit tècniques de cultiu in vitro amb clavellina. El material vegetal s’ha esterilitzat per immersió en una solució diluïda de lleixiu i s’ha manipulat de manera estèril. En tots els casos el medi de cultiu utilitzat ha estat el MS amb una concentració de sacarosa i reguladors de creixement variable segons l’experiment. La incubació dels cultius s’han dut a terme en una cambra amb control de fotoperíode durant 4 setmanes. Els diferents reguladors de creixement han mostrat un clar efecte sobre les seccions de tija. Els explants cultivats en medi lliure d’hormones han crescut menys que els exposats a diverses concentracions de NAA i BA. Aquests tractaments hormonals han originat símptomes de creixement anòmals (engruiximents a la base i vitrificació). La presencia de 2,4-D ha afavorit la formació de cal•lus i d’arrels per organogènesi adventícia indirecta. L’obtenció de plàntules per germinació in vitro de llavors ha permès reduir notablement les pèrdues per contaminació, mentre que el subcultiu d’aquestes ha donat unes tases de micropropagació de 7.2 seccions/plàntula. Ha estat possible aclimatar aquestes vitroplantes per tal d’adaptar-les a les condicions de camp. No hem pogut obtenir organogènesis adventícia ni embriogènesi somàtica a partir d anteres ni hem pogut iniciar un cultiu de cèl•lules a partir dels cal•lus. Tot i la complexitat d’aquestes tècniques, és possible dur-les a terme en un laboratori escolar.

Flooding tolerance and cell wall alterations in maize mesocotyl during hypoxia

This research aimed to characterize the tolerance to flooding and alterations in pectic and hemicellulose fractions from mesocotyl of maize tolerant to flooding when submitted to hypoxia. In order to characterize tolerance seeds from maize cultivars Saracura BRS-4154 and BR 107 tolerant and sensitive to low oxygen levels, respectively, were set to germinate. Plantlet survival was evaluated during five days after having been submitted to hypoxia. After fractionation with ammonium oxalate 0.5% (w/v) and KOH 2M and 4M, Saracura BRS-4154 cell wall was obtained from mesocotyl segments with different damage intensities caused by oxygen deficiency exposure. The cell wall fractions were analyzed by gel filtration and gas chromatography, and also by Infrared Spectrum with Fourrier Transformation (FTIR). The hypoxia period lasting three days or longer caused cell lysis and in advanced stages plant death. The gelic profile from pectic, hemicellulose 2M and 4M fractions from samples with translucid and constriction zone showed the appearance of low molecular weight compounds, similar to glucose. The main neutral sugars in pectic and hemicellulose fractions were arabinose, xilose and mannose. The FTIR spectrum showed a gradual decrease in pectic substances from mesocotyl with normal to translucid and constriction appearance respectively.

Citrus asymmetric somatic hybrids produced via fusion of gamma-irradiated and iodoacetamide-treated protoplasts

The objective of this study was to produce citrus somatic asymmetric hybrids by fusing gamma-irradiated protoplasts with iodoacetamide-treated protoplasts. Protoplasts were isolated from embryogenic suspension cells of grapefruit (Citrus paradisi Macfad.) cultivars Ruby Red and Flame, sweet oranges (C. sinensis Osbeck) 'Itaboraí', 'Natal', Valencia', and 'Succari', from 'Satsuma' (C. unshiu Marcow.) and 'Changsha' mandarin (C. reticulata Blanco) and 'Murcott' tangor (C. reticulata x C. sinensis). Donor protoplasts were exposed to gamma rays and receptor protoplasts were treated with 3 mmol L-1 iodoacetamide (IOA), and then they were fused for asymmetric hybridization. Asymmetric embryos were germinated, and the resulting shoots were either grafted onto sour orange, rough lemon or 'Swingle' (C. paradisi x Poncirus trifoliata) x 'Sunki' mandarin rootstock seedlings, or rooted after dipping their bases in indol-butyric acid (IBA) solution. The products were later acclimatized to greenhouse conditions. Ploidy was analyzed by flow cytometry, and hybridity was confirmed by amplified fragment length polymorphism (AFLP) analysis of plantlet DNAsamples. The best treatment was the donor-recipient fusion combination of 80 Gy-irradiated 'Ruby Red' protoplasts with 20 min IOA-treated 'Succari' protoplasts. Tetraploid and aneuploid plants were produced. Rooting recalcitrance was solved by dipping shoots' stems in 3,000 mg L-1 IBA solution for 10 min.

Lipid peroxidation and seed emergency in progenies of the yellow passion fruit plant

The objective was to evaluate the percentage of emergency plantlets and lipid peroxidation in seeds of 29 half-sib progenies of yellow passion fruit (Passiflora edulis Sims.) after 24 months under storage. The experimental design was completely randomized, with four replications of 50 seeds each, from which the treatments were the progenies (1-29). The evaluation of the percent plantlet emergency was accomplished at 14 and 28 days after sowing. The lipid peroxidation of the seeds was expressed as malondialdehyde (MDA) content that was determined by the TBARS method. Approximately 21% of those half-sib progenies maintained the viability of their seeds for twenty-four months under storage. The results point out a remarkable genetic variability for vigor and emergency of the yellow passion fruit plantlets, with occurrence of individuals with high and other ones with low capacity to maintaining the physiologic quality of their seeds after storage.

Micropropagation of Maclura tinctoria L.: an endangered woody species

Some native species produce seeds with low germination percentage and in most cases with dormancy, which makes the appearance of new individuals by sexual propagation difficult. The Maclura tinctoria has been considered an endangered species due to the indiscriminate use of its wood and low rate of seed germination. In this context, the objective of the present study was to establish an in vitropropagation methodology for this species. Combinations of NAA + BAP, different concentrations of GA3 and combinations IBA + activated charcoal were evaluated for shoot induction, shoot growth and root formation, respectively. The results indicated that the maximum shoot formation was obtained when 5.37 µM NAA + 4.45 µM BAP was used. The use of 5.48 µM GA3 promoted shoot growth. Root formation was observed on explants inoculated in WPM with a pH adjusted to 7.0 and supplemented with 23.62 µM IBA + 4.7 g L-1 activated charcoal. The use of a 70% light screen for 7 days followed by the use of 50 and 30% light screens also for 7 days each provided 97% plantlet survival.

Crescimento inicial e morfologia foliar em plantas de Enterolobium contortisiliquum (Vell.) Morong. E Erythrina velutina Mart. ex Benth, sob estresse hídrico

The Caatinga is the predominant vegetation type in semi-arid region of Brazil, where many inhabitants depend on hunting and gathering for survival, obtaining resources for: food and feed, folk medicine, timber production, etc. It‟s the dry ecosystem with highest population density in the world. The early stages of development are the most critical during the life cycle of a flowering plant and they‟re primordial to its establishment in environments exposed to water stress. Information about adjustments to the growth of the species, correlated with their studies of distribution in Seridó oriental potiguar, are an important ecological and economic standpoint, because they provide subsidies for the development of cultivation techniques, to programs of sustainable use and recovery of degraded areas. This thesis aimed to study the initial growth and foliar morphology in plants like Enterolobium contortisiliquum (Vell.) Morong. (tamboril) and Erythrina velutina Mart. ex Benth (mulungu), species of occurrence in the Caatinga, under water stress. After sowing and emergency, the seedlings were exposed to three water regimes: 450 (control), 225 (moderate stress) and 112.5 (severe stress) mm of water slide for 40 days. Seeding occurred in bags of 5 kg and after the establishment of seedlings thinning was carried out leaving a plantlet per bag. At the beginning the waterings occurred daily with distilled water, passing to be on alternate days after thinning. Twenty and forty days after the thinning seedlings collections were held to be done analysis of growth and biomass partition. When compared to the control group, the treatments with water stress showed reduction in the growth of the aerial part, growth of the greater root, number of leaves and leaflets, dry leaf area and total phytomass in both species, but in general, this effect was most marked for E. velutina. Regarding the partition of biomass, there were few changes throughout the experiment. Morphological changes in the leaves as a function of stress were not significant, however, there was a trend, in both species, to produce narrower leaves, that facilitate heat loss to the environment. It has not been possible to establish a positive relationship between inhibition of growth and distribution of species, whereas E. velutina is a species of most common occurrence in Seridó oriental potiguar. In this way, other aspects should be taken into account when studying the adaptation of species the dry environments, such as salinity, presence of heavy metals, wind speed, etc

Enraizamento de estacas de Caesalpinia echinata Lam. em hidroponia

This study aimed to determine the indole-3-butyric acid (IBA) requirement and proper concentration for Caesalpinia echinata rooting in a hydroponic system for plantlet production. The experiment was conducted in a greenhouse of the 'Faculdade de Ciencias Agrarias e Veterinarias', UNESP, in Jaboticabal, São Paulo state. The vegetal material consisted of 160 stem cuttings that were 11 to 12 cm in length with two pairs of leaves, prepared from young seedlings. The cutting bases were treated by slow immersion in 5% ethanol solution containing 0, 100, 200 and 400 mg L-1 of IBA during 14 hours and by fast immersion in 50% ethanol solution containing 0, 1000, 3000 and 5000 mg L-1 of IBA during 5 seconds. The cuttings were maintained in the hydroponic system for 90 days and, for additional 90 days in plastic bags containing substrate (Plantmax (R)) under intermittent mist. After 90 and 180 days of rooting, the percentage of cuttings that survived, the rooting percentage and the number and length of adventious root were evaluated. Cuttings should be treated with IBA at 100 mg L-1 for 14 hours and placed to root in a hydroponic system.