Morphophenological characterization of ornamental ginger and selection for landscape use ( 1 )

Many species of Zingiber have great ornamental potential, due to durability and exotic appearance of the inflorescences. Despite its large phenotypic variability, they are scarcely exploited or not yet exploited regarding the ornamental potential. To conserve potential ornamental genotypes, and subsidize breeding program, the Agronomic Institute (IAC) maintain a Germoplasm Collection of Ornamental Zingiberales with promising accessions, including Zingiber. The aim was the morphophenological characterization of ten Zingiber accessions and the indication for landscape purposes. A large variation was observed to the evaluated characters: Clump height (CH); Inflorescence visualization (IV); Clump area (CA); Clump density (CD); Leaf stem Firmness (LSF); Number of leaf stems per clump (NLSC); Number of leaves per stem (NLS); Leaf color (LCol); Evergreen tendency (ET); Flower stem growth (FSG); Flower stem length (FSLe); Flower stem diameter (FSD); Flower stem per clump (FSC); Color sensorial perception (CSP); Flower stem weight (FSW); Inflorescence length (IL); Inflorescence diameter (ID); Bracts aspects (BAs); and Flowering season (FSe). The accessions very suitable and with the best performance to use for landscape purpose were Z. spectabile, IAC Anchieta (Z. spectabile), Z. newmanii.


INTRODUCTION
Zingiber is one of the most important genera of the ginger family (Zingiberaceae) but the real number of species is not known.Kishor and Leong-Skornicková (2013) described more than 250 species.Recently, Govaerts et al. (2015), after discarding synonyms, confirmed only 177 valid species.These plants are herbaceous and aromatic living originally in humid regions of the tropical to warmtemperate Asia.Thailand is the country with the richest representation of the genus Zingiber, center of diversity with 56 species, followed by China, with 42 species, of which 36 are endemic (TRIBOUN et al., 2014).
The inflorescence usually arises from the base of the leaf stem, on a underground stem (SABU, 2003).Bracts often bright red, orange, or yellow, closely imbricate or with the apices free, forming small bags filled up with mucilage, comprising a single cincinnus.These exotic appearance of the inflorescences, flowering characterized by many flower stems breaking the ground, the architecture and the typical ginger aroma are positive aspects to be explore in landscape.
V. 24, N o .3, 2018 p. 255-260 Some species are appreciated as ornamental plants due to durability and the exoticism, as an example, Zingiber spectabile (COELHO et al., 2017).Despite its large phenotypic variability, few forms of Zingiber genera are exploited commercially regarding the ornamental potential.Based on the genera amplitude, probably exists many others potential species, geographically restricted and poorly known.
The Germoplasm Collection of Ornamental Zingiberales of the Agronomic Institute (IAC), has promising genotypes, including Zingiber.The objective of this work was the morphophenological characterization of ten Zingiber accessions and the indication for landscape purposes.
A point scoring system was used to determine the accessions most suitable as ornamental plants base on: Inflorescence visualization (IV) (3 points -evident; 2 points -hidden); Clump density (CD) -(3 pointsagglomerated; 2 points -intermediated; 1 point -sparse); Leaf stem firmness (LSF) -3 points -firm; 0 pointsoverturn tendency; Evergreen tendency (ET) -3 pointsyes; 0 points -no; Flower stem per clump (FSC) -3 points -very high and high; 2 points -medium; 1 point -low; Color sensorial perception (CSP) -4 points to very intense color and contrast; 3 points to intense color and contrast; 2 points to intermediated color and contrast; 1 point to pale color with or without contrast; Flowering season (FS) -3 points to more than 4 months; 2 points 4 to 3 months; 1 point -less than 3 months.Base on the total point score, the species were considered poorly suitable (less than 13 points), suitable (13 to 19 points) and very suitable (more than 19 points) to ornamental plants use.

RESULTS AND DISCUSSION
It was observed morphophenological variation between accessions with respect to general characteristics of clump, stems, leaves, inflorescences and flowering (Tables 1 to 5).
About plant height, accessions ranged from 1.80 to 3.30 m and were classified as low (Z.zerumbet), medium (IAC Anchieta, IAC Angatu, IAC Almada, IAC Suanno, Z. newmanii, Z. ottensii and Z. pachysiphon) and high (Z.spectabile and Z. macradenium).All accessions showed evident inflorescence visualization in the clump, except Z. zerumbet whose inflorescence were hidden below the foliage (Table 1).Regarding the clumps area, there was a variation between 0.73 to m at the base and the ranging 2.30 to 5.10 m.It was observed that plants of the accession with large base also had high canopy (e.g.IAC Angatu), and plants with small base had low canopy (e.g.Z. pachysiphon), but neither were the highest nor lowest plant height.Plants with most clustered growth (up to 3.50 m canopy projection) are interesting choices for gardens with limited area, since requires smaller spacing.Base on clump density, accessions with agglomerated and intermediated characteristic could be indicated to hidden walls or fences better than accessions with sparse clumps (Table 1).
Only the accessions Z. zerumbet and Z. ottensii had stems with overturn tendency.Other accessions keeps the stems firm and erect at the clump.The overturn tendency is not directly related to the highest clumps.The number of stems per clump ranged from 16 to 58.The number of leaves was also quite variable, between 20 to 52 leaves per stem, but do not have a direct relation to the number of stems per clump.The leaves color vary from green to dark green.Z. zerumbet was the only accession that foliar stems remains dry on the plant.The others accessions were evergreen during the year (Table 2).About the characterization of inflorescences was noted that all the flower stems were erect except by Z. newmanii and Z. pachysiphon which growth were decumbent.In all the accessions were observed that the length of the flower stems were quite variable in the same clump.The diameter of the flower stems ranged from 2.20 (Z.zerumbet) to 4.30 cm (Z.pachysiphon) (Table 3).About the inflorescence number, the accession IAC Suanno and IAC Anchieta were the most productive, with 60 and 61 stems per clump.Z. zerumbet, with 38 flower stem per clump, was classified as high production.Accessions classified as medium produced among 15 to 30 stems (Z.spectabile, IAC Angatu, IAC Almada, Z. newmanii) and some accessions produced up to 10 inflorescences per plant (Z.macradenium, Z. ottensii and Z. pachysiphon).
Regarding the inflorescence characteristics, it was observed that the flower stem weight varied greatly depending on the accession.It was observed that inflorescence weight is not only influenced by length and width, morphological aspects as having free bracts also seem to influence.The correlation between inflorescence length/width and flower stem weight could be noticed in accessions with free bracts as Z. spectabile and Z. macradenium.
The color of the bracts is also very varied, depending on accession, ranging from green, yellow, orange to darker red on the lips.Most of the accessions have a gradual change color with the inflorescences aging, from the basis for the apex, adding exoticity (Table 4).Thus, the sensorial perception could range for very intense color and contrast to pale color without contrast (Table 3).Table 4. cont.
The flowering season months observed was very early (August to September) as observed in IAC Suanno and Z. macradenium, mid (October to November) as observed Z. spectabile, IAC Anchieta, IAC Angatu, Z. zerumbet and Z. newmanii or late (December to January) as observed IAC Almada, Z. ottensii .Z. pachysiphon was the only accession that produce flowers from May to August.

CONCLUSIONS
The accessions morphophenologic characteristics were influenced by genetic variation and these traits are useful to indicate the type of use.
From the variability observed was possible to select potential accessions for landscaping.
The morphophenologic characterization and genotypic and phenotypic differences conserved in the collection is of great significance to agriculture, to provide important data for the commercial cultivation of potential species and to generate important information for breeding programs.
The accessions very suitable for use to landscape purpose were Z. spectabile, IAC Anchieta (Z.spectabile) and Z. newmanii and present easy inflorescence visualization, leaf stem firmness and evergreen tendency, high number of flower stem per clump, very intense color and contrast sensorial perception.

Table 1 .
Clump characteristics of the Zingiber Accessions.

Table 2 .
Leaf stem characteristics of the Zingiber accessions.

Table 3 .
Flower stem characteristics of the Zingiber accessions.

Table 4 .
Inflorescence characteristics of the Zingiber accessions.