Platanus orientalis L, IBA, Root, Biomass, Branches.

Platanus orientalis L. is a tree species belonging to the family Platanaceae. It is a deep-rooting plant with roots extending the crown area. Chinar tree normally gains a height of about 25 meters with girth exceeding 50 feet in some cases. The bark is grey-brown, flaking and scaly. Leaves are arranged alternately, deeply 3, 5 or 7 lobed, 12-20 cm in length, and palmate with long stalks. Petiole lengths vary from 3 to 8 cm. Flowers are dense, unisexual spherical heads. Fruits are shaped like spheres, about 2 cm in width and are located on the leafstalk. The fruits still stay over on the trees late until the spring. The buds are large, green and protruding. The flowering begins during March-April. It grows in sunny places without continuous shade toleration. It is fit for soils such as sandy, loamy and clay and can tolerate pH from neutral to strongly alkaline. It prefers moist soil but can withstand drought, but not exposure to marine conditions. It can also withstand air-pollution. As per IUCN Red list, it is recognized as endangered in parts of its range due to the expansion of agriculture and irrigation schemes (Anonymous, 2008). P. orientalis L. possibly resulted from accumulation of genetic changes during intercontinental disjunctions and other impediments in geological time (Sert et al., 2008; Pilotti et al., 2009). P. orientalis L. occurs naturally in almost every forest, streams and water basins of Turkey. It is commonly used in Turkey's landscape design and there are many reports of these trees being preserved as monumental trees (Zencirkiran, 2010; Zencirkiran and Erken 2012). Differently, natural standings of P. orientalis L. are found in the Mediterranean region of Southern Europe and South-West Asia particularly in Iran and Turkey.

Platanus orientalis L. is the only species of Platanaceae family found in India and its growth is confined to Jammu & Kashmir State (Kozgar and Khan 2011). The notion that the Mughals brought Chinar trees into the State was denied by Wadoo (2007), according to whom there are many references to the presence of the tree in the state in the historical accounts. Chinar tree has a noteworthy cultural significance and is a common emblem of Kashmir heritage seen in various art and craft designs, embellishment of shawls, wood carving etc. As a very large, wide tree with broad, thick leaves that appear to be horizontally oriented, it is particularly appreciated for its shade and coolness it provides during the summer season. A paste made from the leaves and seeds is applied on eyes for treating ophthalmic disorder. Bark when boiled in vinegar acts as a cure for hernia, toothaches, dysentery and diarrhea. A fabric dye is manufactured from the branches and roots. The wood, called the lace wood, is used for making delicate furniture, ornamentally carved doors, fancy lacquered articles mallets, interior finish, for chopping and dressing of mat as well as fuel wood  (Wadoo, 2007). Given the government restrictions such as J & K Preservation of Specific Trees Act 1967, Land Revenue Act S36 and Chinar rules on the felling of Chinar trees in the Valley in the past, the tree population has declined over the years, suffering much damage due to negligence and human greed. Chinar the 'king of trees' has been under the axe of smugglers. Their number decreased to more than half, from 42000 in 1970 to less than 27000 in the valley (Kozgar and Khan 2011). 

Vegetative propagation techniques have been used to mitigate and overcome the problems which hinder the multiplication of economically important tree species of the forest (Libby and Rauter 1984). It provides a feasible substitute to the customary seedling dependant forestry (Hussey, 1986; Longman and Jenik 1990; Ali and El-Tigani 2003; Dar and Wani 2017). Rooting potential of cuttings is regulated by optimization of several endogenous as well as exogenous factors (Zsuffa et al., 1977; Densmore and Zasada 1978). The endogenous factors that influence the rooting potential of cuttings include maturity of the donor, cutting position, time of collection, pre-conditioning and size of the cutting etc (Nautiyal et al., 2007; Ramesh and Khurana 2007). The exogenous factors that influence the rooting potential of cuttings include rooting medium, humidity, temperature, length of day period and the intensity of light together with other treatments. Hence, it can be said that the potential of cuttings for rooting is influenced by a variety of factors that may function individually or in combination to determine the rooting potential of cuttings. Many attempts have been made to promote the rooting potential of cuttings through different substances such as growth promoters, carbohydrates and many more (Doud and Carlson 1972; Couvillon, 1988). Among different growth promoters IBA have proved its potential by promoting the root initiation and decreased plant mortality (Soni, 1970). Because of its efficacy in wide variety of plant species and its non-toxic behaviour, IBA has turned out to be the best root-promoting chemical (Sadhu, 1999). In many tree species, IBA has been documented as rooting promoter (Gurumurti and Bandari 1988; Chandra and Verma 1989; Pal, 1992; Nautiyal and Rawat 1994). However, effectiveness varies with season, concentration, chemical nature and the mode of treatment (Nanda, 1979). Other factors such as treatment, duration, moisture tension and depth of dipping also influence rooting response of cuttings (Howard, 1972). The studies carried out about the propagation of Platanus species by cutting were particularly intensive on the species of Platanus acerifolia Willd. and it was stated that the factors such as genotype, type of cutting, the position of the cutting-donor shoot on the mother plant, cutting stem diameter humidity and temperature of the rooting medium, and time of collection of the cuttings influence rooting (Grolli et al., 2005). However, there is limited information about the propagation of Platanus orientalis L. by cutting (Dirr and Heuser 2006). The aim of the present study was to standardize optimum concentration of growth hormones and to determine the best section of branches for rooting of Platanus orientalis L. cuttings.

The present study was conducted in the experimental field of Division of Forest Biology and Tree Improvement, Faculty of Forestry, Benhama during the years 2018 and 2019. Cuttings of 8 inches length were prepared from different sections of branches collected from one available Platanus orientalis L. tree located in the vicinity of the campus on 28th of January, 2018.The collected cuttings were dumped in soil till planting on 14th of March, 2019. The cuttings were treated with different concentrations of growth hormone (IBA) before planting. The experiment was laid in polybags filled with sand, soil and FYM in the ratio of 1:2:1 as potting media. The experimental trial was laid at Faculty of Forestry, Benhama as per the details given below

(a) IBA Concentration

(b) Sections of cuttings:

No. of cuttings/treatment combination  :    10

No. of replications :   03

Design   :  Completely Randomized Design (Factorial)

The growth parameters studied were rooting percent (%), root length (cm), average number of roots per plant, sprouting percent (%), shoot length (cm), collar diameter (mm), average number of branches per plant, leaf area (cm2), above ground fresh and dry weight (g) and below ground ground fresh and dry weight (g). The data collected was analyzed using the software OP-STAT.

A. Growth hormone (T)

Results in Table 1 indicated that there was significant impact of IBA on rooting and other root characters of cuttings. A comparatively higher percentage of rooting was found in IBA-treated cuttings. While the percentage of rooting under treated cuttings was lower. Maximum rooting (41.33%) was recorded for IBA@6000ppm. The maximum number of roots with substantial length was induced by this IBA treatment and thus provided a well-developed root system for better establishment of rooted cuttings. Lowest rooting (29.39%) was recorded under untreated cuttings. The reason behind this might be that the application of IBA may have increased the speed of translocation and movement of carbohydrates to the base of cuttings and consequently triggered rooting (Aminah et al., 1995), as the efficiency of auxins to facilitate adventitious root development in stem cuttings is well known (Ragonezi et al., 2010). These results draw support from the findings of Bhattacharjee and Balakrishna (1991) in Hiptage madhblota and Hibiscus, Swamy et al. (2002) in Grewia optiva and Robinia pseudoacacia.

As shown in Table 1, the different concentrations of IBA had a considerable effect on the root characters such as length of root, average number of roots per plants and fresh and dry root biomass. All the concentrations of IBA affected root length and number of roots per plant. However, maximum root length (26.48 cm) and number of roots per plant (8.56) was recorded in IBA@6000ppm, while the minimum root length (13.07 cm) and number of roots (3.67) was recorded in Control. The reason behind this might be that the application of IBA led to the cell division and cell elongation, which promoted the root length (Abidin and Baker 1984) or may be PGRs facilitated the hydrolysis and mobilisation of sugars and nutrients to the base of cuttings (Das et al., 1997). Induction of highest number of roots may be attributed to the fact that, growth regulators in many species, stimulate cambial activity involved in root initiation as confirmed in Pea by Digby and Wanerman (1965). These findings are also in agreement with the findings of Mahmood et al. (2017) who reported increase in root length and number of roots per plant in Paulownia tomentosa on application of Seradix 3. 

With respect to fresh and dry biomass of root, the results revealed that among different concentrations of IBA, IBA@6000ppm recorded maximum fresh and dry biomass (15.49 g) and (5.11 g) respectively. The minimum fresh and dry biomass (6.01 g) and (1.98 g) was recorded under Control. This can be attributed to the maximum root length and number of roots per plant obtained by this concentration. These findings also draw support from the findings of Gehlot et al. (2014) who confirmed increase in biomass of root system on application of IBA while working on Azadirachta indica. Also, Hussein and Khurshid (2017) in Olea europaea L. reported similar findings of increase in biomass of root on application of IBA.

The impact of IBA on cuttings varied considerably with respect to above ground i.e., shoot characters in the present study. Shoot characters viz., sprouting percent, length of shoot, collar diameter, average number of branches per plants, leaf area, fresh and dry biomass of shoot are shown in Table 2. The findings showed that in terms of sprouting percent, various IBA levels differed significantly from each other. IBA@6000ppm recorded the maximum sprouting (98.89%), which was superior over all the other treatments. The lowest (72.22%) was recorded in Control. It was also found that a sharp decrease in sprouting percent of cuttings occurred at higher concentrations (beyond 7000ppm). The upsurge in sprouting percent of cuttings treated with IBA may have resulted from the stimulation of hydrolysis of nutrient reserves and their mobilization. Sprouting in control may have occurred due to the already stored carbohydrates in the cuttings. Differences in sprouting between treatments may be caused by the varying levels of auxin absorption by cuttings. Nanda et al. (1975) confirmed that the use of auxin contributed to the breakdown of starch into soluble sugars, and most of this was used to produce new sprouts. Pain and Roy (1981) reported substantial sprouting gains due to the use of IBA and other chemicals in Dalbergia sisoo. Decline in sprouting at higher concentrations of IBA may be due to super-optimal quantities.

The maximum shoot length (35.38 cm) was found in IBA@6000ppm, which was superior over all the other treatments, while the lowest (17.66 cm) was found in Control. However, IBA at higher concentration (beyond 7000ppm) reduced the shoot length. Sarkisova (1964); Chauhan and Maheshwari (1970) have also documented the ability of IBA to promote shoot growth in Vine and Peach cuttings respectively. Decrease in shoot length at higher concentrations of IBA may be attributed to the toxic or inhibitory effect of IBA at higher levels.

Significant effects of IBA have been observed on collar diameter (mm), number of branches per plant and leaf area (cm2) of cuttings. Maximum collar diameter (6.45 mm), number of branches per plant (2.67) and leaf area (44.67 cm2) was recorded at IBA@6000ppm, while the minimum collar diameter (4.10 mm), number of branches (1.00) and leaf area (20.62 cm2) was recorded in Control. Zarad and Saleh (1994) confirmed that IBA may cause assistance for the development of root, which in turn leads to the absorption of elements as well as conversion of starch to soluble sugars that are transported, contributing to cell division and elongation, thereby improving the qualitative vegetative growth. These results are in conformity with the findings of Mahmood et al. (2017) who reported that the use of Seradix 3 enhanced the length of shoot, number of branches per plant, number of leaves per rooted cutting and collar diameter in Paulownia tomentosa. Moreover, Hussain et al. (2016) in Ulmus villosa and Kumar et al. (2017) in Punica granatum L. reported increase in shoot characters on application of IBA. With respect to fresh and dry biomass of shoot, the results revealed that among different concentrations of IBA, IBA@6000ppm recorded maximum fresh and dry biomass (21.56 g) and (9.43 g) respectively. The minimum fresh and dry biomass (10.07 g) and (4.52 g) respectively, was recorded under Control. This can be attributed to the maximum shoot length, collar diameter and number of branches per plant obtained by this concentration. These findings are in line with the findings of Al-Ma’athid et al. (2009) who reported increase in the fresh and dry weight of shoot system on application of Seradix in Pelaryonium zonale. Similar findings were reported by Hussein and Khurshid (2017) in Olea europaea and L., Mahmood et al. (2017) in Paulownia tomentosa.

B. Type of cutting section (S)

Table 3 (Fig. 1) clearly indicates that there was a significant impact of cutting section on the rooting of cuttings. Among the three types of cuttings, maximum (45.18%) rooting was recorded in basal cuttings, whereas, apical cuttings recorded the minimum rooting (26.38%). The reason behind this may be that apical cuttings are less mature, so it is easy to lose water, dry out and die (Khan et al., 2006) or basal cuttings possess more natural accumulation of endogenous auxin than apical cuttings, which facilitates the initiation and development of roots (Lebrun and Roggemans 1998). These findings draw support from the findings of Ibironke (2013) who reported that basal cuttings of Duranta repens rooted better than apical cuttings.  

Table 1:  Effect of IBA on rooting and root characters of Platanus orientalis L. cuttings.

Figures in parentheses are square root transformed values

Table 2: Effect of IBA on shoot characters of Platanus orientalis L. cuttings.

Figures in parentheses are square root transformed value

Table 3: Effect of type of cutting section on root characters of Platanus orientalis L. cuttings.

Figures in parentheses are square root transformed values

Table 4: Effect of type of cutting section on shoot characters of Platanus orientalis L. cuttings.

Figures in parentheses are square root transformed values

Table 5: Effect of the interaction between IBA and type of cutting section on rooting and root characters of Platanus orientalis L. branch cuttings.

Table 6: Effect of the interaction between IBA and type of cutting section on shoot characters of Platanus orientalis L. cuttings.

Figures in parentheses are square root transformed values

Table 7: Effect of the interaction between IBA and type of cutting section on shoot characters of Platanus orientalis L. cuttings.

Significant effects of cutting sections on the root length and number of roots per plant have been recorded. The results presented in Table 3 (Fig. 1) indicated that maximum root length (24.59 cm) and number of roots per plant (7.77) was recorded in basal cuttings, while as minimum root length (15.73 cm) and number of roots per plant (4.56) was recorded in apical cuttings. These results are consistent with the findings of Ochoa et al. (2002) in Nerium oleander L. who reported that the basal cuttings produced maximum root length and number of roots as compared to apical cuttings.

With respect to fresh and dry biomass of root, the results presented in Table 3 revealed that among three cutting sections, basal cuttings recorded maximum fresh and dry biomass (21.56 g) and (9.43 g) respectively, whereas minimum fresh and dry biomass (10.07 g) and (4.52 g) respectively was recorded for apical cuttings. This can be attributed to the maximum root length and number of roots per plant gained by this cutting section (Al- Bebewat, 2011).  These results are in conformity with the findings of Zalensy et al. (2011) in Populus and Mahmood et al. (2017) in Paulwonia tomentosa. The results in Table 4 clearly indicate that maximum sprouting (89.67%) was recorded for apical cuttings, whereas basal cuttings recorded minimum sprouting (82.31%). These findings are in line with the findings of Ali et al. (2008) who reported that apical cuttings of Berberis aristata DC gave higher sprouting as compared to middle and basal cuttings. The results presented in Table 4 indicated that basal cuttings recorded maximum shoot length (33.32 cm) (Fig. 1), collar diameter (6.18 mm), average number of branches per plants (2.54) and leaf area (39.04 cm2) respectively. Minimum values for shoot length (21.29 cm), collar diameter (4.59 mm), average number of branches per plants (1.38) and leaf area (31.45 cm2) was recorded for apical cuttings. This might be attributed to the fact that different types of cuttings, which differed from one another in the amount of storage nutrient substrates, basal cuttings contain more storage nutrient substrates than intermediate and apical cuttings which contribute to cell division and elongation, leading to the growth and improvement in shoot characters. These results are in line with the findings of Ibironke (2013) in Duranta repens and Kumar et al.(2017) in Punica granatum.

Fig. 1. Comparative shoot and root lengths of different cutting sections.

Results regarding the biomass presented in Table 4 revealed that among three cutting sections, basal cuttings recorded maximum fresh and dry biomass (21.67 g) and (7.96 g) respectively, whereas minimum fresh and dry biomass (11.68 g) and (5.33 g) respectively was recorded for apical cuttings. This can be attributed to the maximum shoot length, collar diameter, average number of branches per plants and leaf area gained by this cutting section (Al- Bebewat, 2011).  These findings draw support from the findings of Zalensy et al. (2011); Populus and Kumar et al. (2017) in Punica granatum.

C. Interaction between growth hormone and type of cutting section (T × S)

As indicated in Table 5, maximum rooting (55.00%) was recorded in S3T7 (basal × 6000ppm), while the minimum rooting (24.00 %) was recorded in S1T1 (apical cutting without any treatment). Interaction between cutting section and IBA concentration was found to be significant. Also, maximum root length (32.42 cm) was recorded in S3T7 (basal × 6000ppm), while the minimum (11.33 cm) was recorded in S1T1 (apical cutting without any treatment). Also, maximum average number of roots per plant (10.67) was recorded in S3T7 (basal × 6000ppm), while the minimum (3.00) was recorded in S1T1 (apical cutting without any treatment). Interactions between cutting sections and IBA concentrations were found to be significant. With regard to root biomass, maximum fresh biomass of root (19.73g) was recorded in S3T7 (basal × 6000ppm), while the minimum (4.69g) was recorded in S1T1 (apical cutting without any treatment). For dry biomass of root, maximum dry biomass of root (6.51 g) was recorded in S3T7 (basal × 6000ppm), while the minimum (1.55 g) was recorded in S1T1 (apical cutting without any treatment). Interaction between cutting section and IBA concentration was found to be significant as evident from Table 5. As evident from Table 6, interaction between cutting section and IBA concentration was found to be non- significant. However, maximum sprouting percent (100.00) was recorded in S1T6 (apical cutting × 6000ppm), S2T7 (middle × 7000ppm) and S3T7 (basal × 6000ppm), while the minimum sprouting (63.33) was recorded in S3T1 (basal cutting without any treatment). Also, maximum shoot length (43.33 cm) was recorded in S3T7 (basal × 6000ppm), while the minimum (15.31 cm) was recorded in S1T1 (apical cutting without any treatment). Maximum collar diameter (7.51 mm) was recorded in S3T7 (basal × 6000ppm), while the minimum (3.79 mm) was recorded in S1T1 (apical cutting without any treatment). Interactions between cutting sections and IBA concentrations were found to be significant. Also, maximum average number of branches (3.00) was recorded in S3T7 (basal × 6000ppm), S3T8 (basal × 7000ppm), S2T7 (middle × 6000ppm) and S2T8 (middle× 7000ppm), while the minimum (1.00) was recorded in S1T1 (apical cutting without any treatment), S1T2 (apical × 1000ppm), S2T1 (middle cutting without any treatment), S3T1 (basal cutting without any treatment) and S2T2 (middle× 1000ppm). Also, maximum leaf area (50.65 cm2) was recorded in S3T7 (basal × 6000ppm), while the minimum (18.22 cm2) was recorded in S1T1 (apical cutting without any treatment). Maximum collar diameter (7.51 mm) was recorded in S3T7 (basal × 6000ppm), while the minimum (3.79 mm) was recorded in S1T1 (apical cutting without any treatment), interactions between cutting sections and IBA concentrations were found to be significant. From Table 7, it is evident that maximum fresh biomass of shoot (30.18 g) was recorded in S3T7 (basal × 6000ppm), while the minimum (7.87 g) was recorded in S1T1 (apical cutting without any treatment). Also, maximum dry biomass of shoot (13.20 g) was recorded in S3T7 (basal × 6000ppm), while the minimum (3.53 g) was recorded in S1T1 (apical cutting without any treatment), interaction between cutting section and IBA concentration being significant. 

Platanus orientalis L. are very difficult to propogate asexually, using this study genetic makeup of superior plants can be propagated easily on vast programme. 

Midhat Bilal, Parvez Ahmad Khan, Ashfaq Ahmad Mir, Nageena Nazir, Amir Bashir Wani, Sajad Ahmad Gangoo, Immad Ahmad Shah and  Asnain Khateeb  (2024). Effect of various Concentrations of Growth Hormone (IBA) and Types of Cutting Sections on Rooting and Growth of Platanus orientalis L. Branch Cuttings. Biological Forum – An International Journal, 16(7): 44-52.