Spines growth responses of dragon blood (Daemonorops draco) rattan seedlings in several compositions of organic media

Cultivation of Daemonorops draco is one of the conservation strategies to conserve its population in nature. Complete data and information about morphology are needed to support cultivation techniques. There has been much research on the morphology of D. draco, but the research of rattan spines is lack. Rattan spines have an important function in protecting themselves against herbivores or seed predators. Growing media is one of the factors that influence the growth of rattan spines. We studied the growth of rattan spines from several compositions of organic media in nurseries. The experiment was arranged in a completely randomized design, with five treatments and three replications. The treatments were compositions of organic media content, i.e.: 0%, 25%, 50%, 75%, and 100%. The variables observed were the number of rattan spines, spines color, and spines angle. Our results showed that the media composition of 75% organic matter tends to show higher spines growth response even though statistically not significantly different with 100% mineral soils. Spine’s color was light green to yellow. Spines angle was pointed downward towards the grounds.


Introduction
Daemonorop draco is one of the rattan species that produces a red resin, traditionally known as jernang [1]. In Jambi, jernang rattan has many benefits for economic, ecological, and social value. This is why the jernang rattan has been nominated as a superior local plant [2]. This species has the potential to be developed outside of forest areas [3] and is also suitable to be cultivated in rubber agroforestry systems in a minimum area of 1.28 hectares [4][5][6].
Recently, the source of jernang was decreasing and threatened while its demand is increasing [7]. A large amount of jernang has been produced from rattan extraction in natural forests. In contrast, natural forests as a rattan habitat are degraded and deforested due to illegal logging, forest fires, and land conversion [5,8]. For example, [9] reported that the population of D. draco in Jebak forest-Jambi declined because of illegal logging and forest encroachment.
Cultivation of D. draco is one of the conservation strategies to conserve its population in nature [10]. Although in terms of genetic diversity, the cultivated population has a lower genetic diversity value than the natural population [11]. Complete data and information about morphology are needed to support cultivation techniques. Spines are various parts of rattan morphology. There has been much research on the morphology, but research on rattan spines is lacking [12]. Rattan sheaths have spines for protection themselves against herbivores or seed predators [13]. Rattan spines play a significant role in supporting the rattan as it grows over trees and other plants in the rainforest [14]. Growing media is one of the factors that influence the growth of rattan spines. Organic media can be used as a growth media and gave the growth response that was not different from mineral soil media [15]. Organic media can be applied as an alternative growing media for substitutes of topsoil. The advantages of organic media are easy, cheap, and abundant [16].
This study aimed to investigate the spines growth of leaf sheaths from several compositions of organic media in nurseries and the morphology. The results of this study can be used to complete the data of rattan morphology and to support for species identification and cultivation technique.

Material
The material used was seedlings of jernang rattan from 2.5 to 8.5 months age grown in organic media ( Figure 2). Organic media used was composted wood sawdust, which comes from sawmill waste. Mineral soil was taken from topsoil around the nursery, while seeds were collected from mother trees in Lamban Sigatal Village, Pauh Sub-district, Sarolangun district, Jambi Province. Seeds were germinated in August 2010 and transplanted into polybags in November 2010. Seedlings were placed in the shade with an intensity of 65%. Seedlings were put in a puddle to save water. Chemical properties of the media was described in Table 1 [15].

Research method
This investigation is experimental research to study the spines growth of leaf sheaths on several compositions of organic media. The experiment design was arranged in a completely randomized design (CRD) with five treatments and three replications. The treatments were compositions of organic media content, i.e.: 0% (100% mineral soil), 25%, 50%, 75%, and 100%. Mixing organic matter and mineral soil based on volume (%).
The variables observed were the number of spines of leaf sheaths, spines color, and spines angle. The observation was carried out every 1.5 months from 2.5 (seedlings transplanted into polybag) to 8.5 months age (seedlings ready to be planted in the field). Descriptive analysis and inferential analysis were used to analyze the obtained data. Data of number and leaf sheath spines were analyzed by analysis of variance using the linear model [17].

Effect of organic media to growth of leaf sheath spines
Results of analysis of variance on the effect of media on the growth of leaf sheath spine from 2.5 to 8.5 months age are presented in Table 2. Table 2 showed that growing media has no significant influence on the number of leaf sheath spines statistically. Organic media was not significantly different to the growth of leaf sheath spines. Organic media like composted wood sawdust had a good chemical properties and higher major nutrients (N, P, K, Mg, and Ca), pH, and CEC [15]. Organic media also has excellent physical properties because it increased saturated hydraulic conductivity and gas diffusivity coefficient. The physical properties of growing media had correlated with plant growth (dry weight) [18].
Based on descriptive analysis, organic media tend to show higher spines growth response than without organic media (100% mineral soil) (Figure 3). The spines of leaf sheath began to appear at 5.5 months age. At the age of 7 and 8.5 months, growing media with 75% organic matter content shows a growth rate of 9 and 14 spines of the leaf sheath, whereas mineral soil media (0%) produce a growth rate of 6 and 11 spines.  5 Our result showed that the spines color of seedlings was light yellow. Spines angle was pointed downward towards the ground. The spines of Daemonorops have different shapes and colors. For example, D. robusta has thin spines shape and whitish to black in color. D. sabut has smooth spines, which are black and brown [20]. The downwards spine angle might be specifically designed to discourage climbing leaf and seed predators [12].

Morphology of leaf sheath spines
The leave consists of a tubular base wrapped by a leaf sheath, which arises from the node on the stem. The sheath narrows into the petiole that continues into the rachis or leaflet-bearing portion of the leaf. Spiny leaf sheaths cover the stems of rattan (Figure 4). Spine arrangement on the leaf sheath is remarkably diverse and frequently of diagnostic importance [19]. [12] also reported that the leaf sheath spines have regular shapes and therefore are reliable for species identification. The number and arrangement of spines varied from one species to another and from genus to other genus and even between individual stems of the same species.