Passiflora alata in vitro organogenesis was studied based on explant type, culture medium composition, and incubation conditions. The results indicated that the morphogenic process occurred more efficiently when hypocotyl segment-derived explants were cultured in media supplemented with cytokinin and AgNO 3 incubated under a 16-h photoperiod. The shoot bud elongation and plant development were obtained by transferring the material to MSM culture medium supplemented with GA 3 and incubated in flasks with vented lids. Histological analyses of the process revealed that the difficulties in obtaining plants could be related to the development of protuberances and leaf primordia structures, which did not contain shoot apical meristem. Roots developed easily by transferring elongated shoots to 1/2 MSM culture medium. Plant acclimatization occurred successfully, and somaclonal variation was not visually detected. The efficiency of this organogenesis protocol will be evaluated for genetic transformation of this species to obtain transgenic plants expressing genes that can influence the resistance to Cowpea aphid borne mosaic virus.

Monteiro-Hara, A, Meletti, L. M. M., and Piedade, S. M. De S. 2011. Genetic transformation of passionflower and evaluation of R| and R, generations for resistance to Cowpea aphid bortie mosaic virus. Plant Dis. 95; 1021 -1025.We report on the production and evaluation of passionflower transgenic lines for resistance to Cowpea aphid home mosaic virus (CABMV). Genetic transformation was done using Agrobacterium tutnefaciens and transgene integration was confirmed by Southem blot analyses, resulting in nine transgenic lines for 'IAC 275' and three for iAC 277". Tran.sgenic lines were clonally propagated and evaluated for resistance to CABMV. After the third inoculation, under higher inoculum pressure, only propagated plants of the transgenic line T16 remained asymptomatic, indicating a high resistance to infection with CABMV, This transgenic line was self-pollinated and the R| generation was evaluated together with the R| generation of another resistant transgenic line (T2) identified previously. Plants were inoculated with CABMV by means of viruliferous Myzus nicotianae. All 524 T2R, plants became infected, whereas 13 of 279 T16R| remained asytnptomatic after four successive inoculations. A TlóR^ generation was obtained and plants were inoculated with CABMV mechanically or by aphids. After successive inoculations, 118 of 258 platits were symptomless, suggesting that the resistance to CABMV was maintained in the plant genome as the homozygous condition was achieved. Five selected resistant TI6Ri plants which contained the capsid protein gene are being crossed for further analyses.Brazil is the worid's largest producer of passion fruit, with an estimated planted area of 44,300 ha and fruit yield of 615,196 t (12), Corresponding author; J. A. M. Rezende,

A protocol for the in vitro culture of Cucurbita pepo cv. Caserta was studied, using a cotyledon segment with an attached hypocotyl fragment as an explant. First, to determine the optimal seedling age, explants were collected from 4 to 6-day-old in vitro germinated seedlings and cultured in MS basal medium supplemented with benzylaminopurine (BAP, 4.5 µM), under a 16-h photoperiod at 27ºC. Based on the results obtained, the explants collected from the 4-day-old seedlings were then cultured in MS basal medium supplemented with different concentrations of BAP (0, 1.1, 2.2, 3.3, 4.5, or 5.5 µM) and incubated under a 16-h photoperiod at 27ºC. In vitro organogenesis was most efficient with explants collected from 4-day-old seedlings cultured in medium supplemented with 4.5 µM of BAP. After 4 weeks of incubation the development of adventitious buds at the cotyledon/hypocotyl junction could be observed. These buds were transferred to elongation and rooting medium and the developed plants were acclimatized to greenhouse conditions. The morphogenic process was characterized using light and scanning electron microscopy analyses to confirm the organogenesis. The results showed that this alternate explant is efficient for in vitro culture of zucchini squash cv. Caserta. The protocol will be further examined for future use in genetic transformation experiments in this species.