BIOTECHNOLOGY:

Conventional techniques of vegetative propagation of Acca sellowiana based on  cuttings are difficult because of the low rates of success. Apparently, the phenol oxidation negatively affects the percentage of rooting Micropropagation techniques have been used to overcome such problems. Various reports of the application of tissue culture techniques based on organogenesis in this species have been published elsewhere (Guerra et al. 2001).

These protocols have been based on the culture of nodal segments, apical and axillary bud, and microcuttings, generally showing low efficiency in terms of regenerative potential. In parallel, research efforts have been alternatively directed to the induction and control of somatic embryogenesis (Guerra et al. 2001).

(Guerra et al. 2001).

BIBLIOGRAPHY:

GUERRA, M. DAL VESCO, L. DUCROQUET, J. NODARI, R. & DOS REIS, M. Somatic embryogenesis in goiabeira serrana: genotype response, auxinic shock and synthetic seeds. Rev. Bras. Fisiol. Veg. [online]. 2001, vol.13, n.2 [cited  2011-05-20], pp. 117-128 . Available from: <http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-31312001000200001&lng=en&nrm=iso>. ISSN 0103-3131.  doi: 10.1590/S0103-31312001000200001.

POLLINATION:

Acca sellowiana (Berg) Burret is a predominantly allogamous species with hermaphrodite flowers that has barriers to self-fertilisation such as dichogamy by protogyny and self-incompatibility, and it´s hard to identify when self-incompatibility occurs in A. sellowiana flowers submitted to self-pollinations (Finatto et al. 2011). 

Pollinations were made using nine known self-incompatible accessions in several treatments including manual cross-pollination, manual self-pollination, no pollination and natural pollination. Flowers were pollinated and pistils collected at times ranging from 1 to 30 days after pollination (DAP) (Finatto et al. 2011).

In both cross- and self-pollinations the fertilisation occurred from 18 DAP and the zygote was visualised at 24 and 26 DAP, respectively. The abscission of the self-pollinated flowers increased from 26 DAP onwards, when significant differences (P < 0.05) were found for the percentage of abscission among self-pollinated and cross-pollinated flowers. At 30 DAP, 72% of self-pollinated flowers were abscised (Finatto et al. 2011). 

The size of ovules and ovaries of self-pollinated flowers showed no significant difference from those of non-pollinated flowers throughout 30 DAP, while those from cross-pollinated flowers were significantly larger (P < 0.05) than the other treatments from 22 and 24 DAP, respectively. After 40 DAP, there was no fruit development in self-pollination and non-pollination treatments (Finatto et al. 2011). 

It needs to bring greater clarity to the mechanism of self-incompatibility in A. sellowiana, indicating late-acting self-incompatibility occurring through the rejection/abscission of self-pollinated flowers precisely after syngamy and zygote formation (Finatto et al. 2011).

BIBLIOGRAPHY:

1. FINATTO, T. DOS SANTOS, K. STEINER, N. BIZZCOCHI, L. HOLDERBAUN, D. DUCROQUET, J. GUERRA, M. & NODARI, R. Late-acting self-incompatibility in Acca sellowiana (Myrtaceae). Australian Journal of Botany.  [online]. 2011. [cited  2011-05-20], 59, 53–60. Available from: <http://www.publish.csiro.au/paper/BT10152.pdf>

MUTATIONS:

Many anomalous somatic embryos were detected such as fused ones, some lacking or with poorly developed cotyledons, others with supernumerary cotyledons, and also embryos with fused cotyledons (cupuliform cotyledons) (Pescador et al, 2008).

The gene mutant of arabidopsis, characterized by a variable degree of inclined cell division planes, presented marked zygote phenotypical alterations. Arabidopsis thaliana (L.) Heynh. mutant plants for normal organization of shoot apical meristems as the shootmeristemless (stm), wuschell (wus) and gurke (gk) present profound phenotypical changes. Two other functionally redundant genes CUP-SHAPED COTYLEDON 1  (CUC1) and  2 (CUC2), are also necessary for the separation of the cotyledon primordia and for the formation of a functional shoot apical meristem in arabidopsis. Embryos with fused cotyledons and absence of cotyledons lacking shoot apical meristem are similar to what was found in some of the somatic embryos of Acca sellowiana (Pescador et al, 2008).

The ease by which somatic embryogenesis is induced in Acca sellowiana would largely result from the relatively high level of 2,4- D present in the culture medium. Deleterious effects of  2,4-D on the in vitro chromosomal feature such as endoreduplication, aneuploidy and polyploidy have been observed in several cases (Pescador et al, 2008).

In fact, 2,4-D can change the conformation of the PIN protein, negatively interfering with the efflux of IAA, and altering the normal establishment of the apical-basal somatic embryos axis. At least two arabidopsis mutants for auxin signaling (bdl and mp) were shown to block the formation of the central and basal regions of the embryo and these defects could be traced back to the two-cell stage where the apical cell divides horizontally rather than vertically. Comparative hormonal studies performed with corresponding zygotic and somatic 2,4-D-formed embryo stages of Acca sellowiana showed profound differences in their ABA, IAA and cytokinins endogenous levels (Pescador et al, 2008).

BIBLIOGRAPHY:

1. PESCADOR, R. KERBAUY, G. VIVIANI, D.  &  KRAUS, J. Anomalous somatic embryos in Acca sellowiana (O. Berg) Burret (Myrtaceae). Rev. bras. Bot. [online]. 2008, vol.31, n.1 [cited  2011-05-20], pp. 155-164 . Available from: <http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042008000100014&lng=en&nrm=iso>. ISSN 0100-8404.  doi: 10.1590/S0100-84042008000100014.

PURE LINES :

The species can be divided into two "types" that have different characteristics especially with  relation to plants. The typical group, or "Type Brazil "has plants with sheets of abaxial light green, whitish pubescence short and sparse, the fruits have large seeds (0.45 to 0.60 g for 100 seeds). The "Type Uruguay" presents plants with leaves of the abaxial white-gray with dense white pubescence Felt kind, small seeds (0.20 g per 100 seeds) (Santos et al. 2005). 

A second distinction between the types can be made According to the geographical origin of the germplasm. The type of hits Brazil present are found in woods and copses of slopes that characterize the areas of high altitude grassland of southern Brazil, between 1,200 and 1,600 m altitude and above 1,000 m in the Rio Grande do Sul, where frosts and temperatures down to -10 ° C can occur with average annual temperature below or close to 16 ° C and relief favoring the formation of sparse woods and forests Araucaria, regardless of soil type (Santos et al. 2005). 

The plants of type "Uruguay", coming mainly from northern Uruguay, appear in the wooded mountains of southwestern New South Wales and in areas of greater relief from Uruguay, with average annual temperature also at around 16 ° C. However caution must be taken with these proposals, the fact that these ratings were made in the absence of studies on genetic diversity. The few studies have yet to demonstrate to the unequivocal the existence of these types (Santos et al. 2005).

BIBLIOGRAPHY:

1. SANTOS, K. STEINER, N. DUCROQUET, J. GUERRA, M. & NODARI, R. Domestication of the pineapple-guava (Acca sellowiana) in south Brasil. Agrociencia. [serial on the Internet]. 2005. [cited  2011  May  19] ; Vol. IX N° 1 y N° 2  pág. 29 - 33. Available from: http://www.fagro.edu.uy/agrociencia/VOL9/Agrociencia.%20(2005)%20Vol.%20IX%20Num%201%20y%20Num%202.pdf

GENETIC MAPPING:

The genetic variability of this species is normally high at the center of origin, and information on such variability is essential for A. sellowiana conservation, breeding and commercial production. In general, specific phenotypes of discreet variation are used as morphological markers. However, a limited number of morphological markers have been identified for this species, which are frequently affected by dominance and epistatic gene interactions, environmental effects and pleiotropy. To overcome such problems, molecular markers can be used to help genetic characterization and breeding (Dos santos et al, 2007).

Among the classes of molecular markers available to identify variation at DNA level, the microsatellites, or simple sequence repeats (SSRs), are considered ideal markers for genetic studies because they combine several suitable features: (i) co-dominance; (ii) multiallelism; (iii) high polymorphism, allowing precise discrimination even of closely related individuals; (iv) abundance and uniform dispersion in plant genomes; and (v) the possibility of efficient analysis by a rapid and simple polymerase chain reaction (PCR) assay. In addition, for the amplification of microsatellite loci, a knowledge of their DNA sequence is required, and this is an expensive and time consuming process. However, the approach of using enriched libraries with repetitive sequences has been very successful in developing SSRs at a reasonable cost (Dos santos et al, 2007). 

The ability to use the same microsatellite primers in different plant species, called transferability, depends on the extent of sequence conservation in the primer sites flanking the microsatellite loci and the stability of those sequences during evolution. It has been shown that closely related species are more likely to share microsatellite priming sites than more distantly related ones, but it is possible to transfer functional microsatellite primers even from more distantly related species (Dos santos et al, 2007).

Because there are no microsatellites available for A. sellowiana, the Eucalyptus spp. primers of microsatellite loci can be used as an alternative to find similar regions on the A. sellowiana genome, since they belong to the same family (Dos santos et al, 2007).

(Dos santos et al, 2007).

(Dos santos et al, 2007).

 (Dos santos et al, 2007).

BIBLIOGRAPHY:

1. DOS SANTOS, K.; WELTER, L.; DANTAS, A.; GUERRA, M.; DUCROQUET, J.; NODARI, R. Transference of microsatellite markers from Eucalyptus spp to Acca sellowiana and the successful use of this technique in genetic characterization. Genet. Mol. Biol.  [serial on the Internet]. 2007  [cited  2011  May  10] ;  30(1): 73-79. Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572007000100014&lng=en.  doi: 10.1590/S1415-47572007000100014.

FEIJOA GENEBANKS:

1) USDA, United States Department of Agriculture

    ARS, Agricultural Research Service
    NPGS, National Plant Germoplasm System

    GRIN, Germoplasm Resources Information Network

16 Accessions:

HPSI 69 N04-12
1. PI 9078
2. PI 12850
3. PI 15818
4. PI 15819 Smooth.
5. PI 15820 Winter.
6. PI 26120
7. PI 26121
8. PI 27957
9. PI 31389 Hehrei.
10. PI 31390
11. PI 32151
12. PI 32152
13. PI 38970
14. PI 39555
15. PI 88570 Magnifica (USDA, 2011).

2) Secretaria de Estado da Agricultura e Desenvolvimiento Rural, Brazil.

EPAGRI, Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina.

São Joaquim Experimental Station, Santa Catarina State.

AGB, Active Germplasm Bank of Goiabeira-serrana.

(Dos santos et al, 2007).

BIBLIOGRAPHY:

1. USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland. URL: http://www.ars-grin.gov/cgi-bin/npgs/html/DispPN.pl?16573 (07 May 2011).
2. DOS SANTOS, K.; WELTER, L.; DANTAS, A.; GUERRA, M.; DUCROQUET, J.; NODARI, R. Transference of microsatellite markers from Eucalyptus spp to Acca sellowiana and the successful use of this technique in genetic characterization. Genet. Mol. Biol.  [serial on the Internet]. 2007  [cited  2011  May  10] ;  30(1): 73-79. Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572007000100014&lng=en.  doi: 10.1590/S1415-47572007000100014.

ORIGIN PLACE OF THE FEIJOA:

The Feijoa (Acca sellowiana (O. Berg) Burret) before Feijoa sellowiana Berg, is a Myrtaceae native from south america, the area is stretching from southern of Brazil, over Uruguay and on the upper west side of Paraguay and of northeastern of Argentina (Schumann & Ludders, 1992). The first description was made by Berg from botanical samples collected by Sellow (whose derived sellowiana) in southern Brazil in 1854, the name feijoa derives, in turn, from the director of the museum of history of St. Sebastian (Brazil), G. de Silva Feijoo (Cacioppo, 1988).

The Feijoa cultivation has been established in other subtropical countries like New Zealand (country where it has done the most research on this fruit), Algeria, Cuba, North Africa, France, Italy, Japan, Russia, United States (California and Florida), Israel, Spain and Uruguay (Cacioppo, 1988; Jackson & Looney, 1999). The arrival of Feijoa to Colombia, is recorded after 1900, it is not known the exact date of introduction to Colombia, but in 1937 Robledo mentions in his book of botany lessons (Campos,1993), although some authors argue that this species was already known in the country.

BIBLIOGRAPHY:

1. CACIOPPO, O. 1988. La feijoa. Ed. Mundi-Prensa (Madrid). 13, 26p.
2. CAMPOS, T. 1993. Propagación de la feijoa por marcotaje modificado (estudios preliminares). AGRO-Desarrollo. 4(1-2), 84-88p.
3. JACKSON, D. & LOONEY, N. 1999. Temperate and subtropical fruit production. CABI Publishing (New York), 267-269p.
4. SCHUMANN, M. & LÜDDERS, P. 1992. Cultivation of feijoa: possibilities and limits in Colombia. Erwerbsobstbau (Alemania). 34(4), 110-112p.