環境因子與無機養分對擎天鳳梨葉片解剖與生理之影響

行政院國家科學委員會專題研究計畫 成果報告

環境因子與無機養分對擎天鳳梨葉片解剖與生理之影響

研究成果報告(精簡版)

計 畫 類 別 ： 個別型

計 畫 編 號 ： NSC 96-2313-B-002-028-

執 行 期 間 ： 96 年 08 月 01 日至 97 年 07 月 31 日

執 行 單 位 ： 國立臺灣大學園藝學系暨研究所

計 畫 主 持 人 ： 葉德銘

計畫參與人員： 教授-主持人(含共同主持人)：葉德銘

碩士-專任助理人員：林昭儀

報 告 附 件 ： 出席國際會議研究心得報告及發表論文

處 理 方 式 ： 本計畫可公開查詢

中 華 民 國 97 年 06 月 04 日

HORTSCIENCE43(1):146–148. 2008.

Potassium Nutrition Affects Leaf

Growth, Anatomy, and Macroelements

of Guzmania

Chao-Yi Lin and Der-Ming Yeh

Department of Horticulture, National Taiwan University, No. 1, Roosevelt

Road Section 4, Taipei, Taiwan, Republic of China

Additional index words. bromeliad, chlorophyll, mineral deficiency, water storage tissue Abstract. Guzmania lingulata (L.) Mez. ‘Cherry’ plants were grown in coconut husk chips. All plants were given 8 mMnitrogen (N), 2 mMphosphorus (P), 4 mMcalcium (Ca), and 1

mMmagnesium (Mg) at each irrigation with potassium (K) concentration at 0, 2, 4, or 6

mM. After 9 months, K concentration did not alter the number of new leaves, and shoot

and root dry weights. Increasing K concentration did not affect the length but increased the width of the most recently fully expanded leaves (the sixth leaves). Plants under 0 K exhibited yellow spots and irregular chlorosis on old leaves being more severe at the middle of the blade and leaf tip. Numbers of leaves with yellow spots or chlorosis decreased with increasing K concentration. Chlorenchyma thickness was unaffected by K concentration, whereas water storage tissue and total leaf thickness increased with increasing K concentration. Leaf N concentration in the sixth or 10th leaf was unaffected by solution K concentration. However, plants at 0 mMK had higher N concentration in the

14th leaf than those in sixth and 10th leaves. Leaf P, Ca, and Mg concentrations decreased with increasing solution K concentration. K concentrations were higher in the sixth leaf than the 14th leaf in plants at 0, 2, or 4 mMK, whereas leaf K concentration was 15 g
kg–1

on dry weight basis in the sixth, 10th, or 14th leaves in plants treated with 6 mMK.

Differential growth and quality responses to potassium (K) have been reported for foliage plants. Potassium deficiency is a wide-spread disorder on many palm species world-wide (Chase and Broschat, 1991). Under conditions of K deficiency, K from the oldest leaves is mobilized for use by the newly expanding leaves. Thus, removing potassium-deficient leaves accelerates rate of decline in Phoenix robelenii O’Brien (Broschat, 1994). The oldest leaves are more suitable for analyzing K status in coconut and Canary Island date palms (Broschat, 1997).

Although bromeliads have been widely used for indoor foliage plants or landscape decoration for decades, most research on K or other nutrient uptake in bromeliads has been done in their habitats (Benzing, 2000; Richardson et al., 2000). Published report on nutrient supply for production is presently limited. In one report, grade of Aechmea fasciata Baker was unaffected by increasing K from 50 to 150 mg/10-cm pot per month (Poole and Conover, 1976). The tropical foliage species Aglaonema commutatum Schott, however, did not respond to increased K from 80 to 320 mg/15-cm pot per month (Poole and Conover, 1977). Spathiphyllum ‘Sensation’ initially grew normally under K-deficient conditions with healthy appear-ance (Yeh et al., 2000).

Irregular yellowish areas on the old leaves have been observed on Guzmania lingulata (L.) Mez. ‘Cherry’. These affected plants tend to produce incurved leaves after storage. Yellow spots on old leaves have been reported as symptoms of K deficiency for palms (Bro-schat, 1997), Phalaenopsis (Wang, 2007), and Spathiphyllum ‘Sensation’ (Yeh et al., 2000).

No controlled studies have been con-ducted to characterize the specific symptoms of Guzmania K deficiency and to quantify K requirements. The objective of this study was to determine the growth, leaf anatomy, and macronutrient concentrations of Guzmania lingulata ‘Cherry’ under various solution K concentrations.

Materials and Methods

Nonflowering plants of Guzmania lingu-lata ‘Cherry’ with 10 to 13 fully expanded leaves were planted in plastic containers containing 0.9 L of 1-cm diameter coconut husk chips commonly used for commercial production of bromeliad. The experiment was conducted from 30 May 2005 to 9 Mar. 2006 and all plants were grown in a 30% shaded greenhouse with an average noontime light intensity of 390mmol
m–2
_s–1_{and mean}

daily temperature of 25C. The uppermost leaf was marked for each plant for determin-ing the number of new leaves to be produced. Nutrient solutions were made from K2SO4, NaH2PO4
2H2O, NH4NO3, Ca(NO3)2
4H2O, MgSO4
7H2O, and CaCl2
2H2O to provide (in mM) 8 nitrogen (N), 2 phosphorus (P),

4 calcium (Ca), 1 magnesium (Mg), 2 sodium, and 2 chloride with K concentration at 0, 2, 4,

or 6 mM. Plants were each fertigated weekly with 0.2 L of nutrition solution. Sulfate concentration increased from 0 to 3 mMas a necessary result of applying the K treatments. Tap water [electrical conductivity (EC) at 0.2 dS
m–1_{] was used to prepare all solutions.}

The micronutrients of the tap water was (mg
L–1_{) 0.017 iron and 0.016 zinc measured}

with an inductively couples argon plasma (ICP) emission spectrometer (Thermo Jarrell Ash Co., Boston, NY). At the end of exper-iment, the medium EC and pH were mea-sured using pourthrough extracts (Wright, 1986). As K concentration increased from 0 to 6 mM, the medium EC ranged from 0.53

to 0.92 dS
m–1_{as measured with a}

conduc-tivity meter (SC-170; Suntex, Taipei, Tai-wan), and pH increased from 5.7 to 6.0 as measured with a microcomputer pH meter (6171; Jenco Instruments, San Diego, CA).

At the end of the experiment, numbers of new leaves and leaves with yellow spots ($1- to 2-mm diameter) or chlorosis were recorded in each treatment. The most recently fully developed leaf (leaf 6 from the apex) from all six plants in each treatment was sampled for measuring leaf length and width. Relative chlorophyll contents of the sixth and 15th leaves from all six plants in each treatment were measured in situ with a chlorophyll meter (SPAD-502; Minolta Camera Co., Tokyo). Three SPAD-502 read-ings were taken on the middle of the blade. Epidermis impressions were made on the fresh intact seventh leaves by applying a transparent glue, which covered3 · 3 cm2

of the abaxial surface. After drying (2 to 3 min), the imprints were removed from the leaf with a clear adhesive tape and mounted on a microscope slide. Stomatal frequency and percentage of opening stomata (numbers of opening stomata/total stomata number) were determined. Samples were taken from all plants, each with 10 replications per plant. The seventh 1eaf was cross-sectioned to measure leaf thickness. Shoots and roots were collected and oven-dried at 70C for 72 h to determine dry weights. Relative water content of the whole leaves was calculated as [(fresh weight – dry weight)/fresh weight]· 100%. Samples were taken from all treat-ments, each with six replications. Concen-trations of N in leaves 6 (most recently expanded leaf), 10 (middle leaf), and 14 (old leaf) from all plants in each treatment were determined with the Kjeldahl procedure and that of P, K, Ca, and Mg were analyzed with an ICP emission spectrometer.

This experiment was arranged in a com-pletely randomized design. Treatments were replicated six times with a single plant per replication. Linear and quadratic regression analyses were performed and presented using Sigma Plot 8.0 programming (SPSS, Chicago).

Results and Discussion

The number of new leaves and shoot and root dry weights were unaffected by K concentration in the nutrient solution (Table 1). Similarly, grade of Aechmea fasciata was

Received for publication 30 May 2007. Accepted for publication 29 Aug. 2007.

1_Professor.

2_{To whom reprint requests should be addressed;}

e-mail [email protected]

unaffected by increasing K from 50 to 150 mg/10-cm pot per month (Poole and Con-over, 1976). Aglaonema commutatum did not respond to increased K from 80 to 320 mg/ 15-cm pot per month (Poole and Conover, 1977).

Reducing solute K+_{provision may limit}

lateral cell expansion. The width of the most recently fully expanded leaves increased with increasing K concentration to 4 mM(Table 2).

This is consistent with previous reports that K is known as the dominant osmoticum and contributes to cell enlargement and leaf expansion (Fricke et al., 1994; Fricke and Flowers, 1998; Shabala et al., 2000). Wang (2007) reported that Phalaenopsis produced wider leaves as K concentration in the nutri-ent solution increased.

The 0-K treatment reduced chlorophyll in the old leaves. Numbers of leaves with yellow spots and irregular chlorosis decreased with increasing K concentration (Table 2; Fig. 1). After treatments for 3 months, the old leaves on plants deficient of K began to exhibit yellow spots. Similar yellow spots as a result of K deficiency have been reported for palms (Chase and Broschat, 1991), Phalae-nopsis (Wang, 2007) and Spathiphyllum ‘Sen-sation’ (Yeh et al., 2000). Symptoms of severe K deficiency were expressed as uneven chlo-rosis of old leaves being more severe at the middle of the blade and leaf tip.

Bromeliads have a unique water storage tissue to overcome drought stress. In Tilland-sia ionantha Planch (Nowak and Martin, 1997), the cross-sectional area of the water storage tissue decreased rapidly and was completely exhausted after 50 d of drought treatment, whereas the cross-sectional area of the chlorenchyma declined by only 12%. Chlorenchyma thickness was unaffected by K concentration in Guzmania, whereas water storage tissue and total leaf thickness increased with increasing K concentration (Table 3; Fig. 2). Because Guzmania reduced leaf water storage tissue under K deficiency, the K-deficient leaves may be more suscep-tible to severe drought stress and become incurved.

Relative water content increased with increasing K concentration in Guzmania (Table 3), likely the result of increased water storage tissue. Stomatal frequency on the recently fully developed leaves was unaf-fected by K concentration, whereas the per-centage of opening stomata decreased with increase in K concentration (Table 3). This is

consistent with Arguero et al. (2006) who reported that K starvation increased gS in olive trees, especially under water stress conditions. It is well documented that K serves a crucial function for cell osmoregu-lation, turgor maintenance, cell expansion, and stomatal function (Shabala, 2003).

Nitrogen concentrations in the 10th and 14th leaves were unaffected by solution K concentration (Fig. 3). The sixth leaves, however, had higher N concentration in plants under 0 K compared with those with 2 to 6 mMK. Increasing absorption of NH4+ can displace the role of K+ _{in osmotic}

function (Xu et al., 2002), and that may explain why higher leaf N concentration in the K-deficient Guzmania.

Leaf P concentration also decreased with increasing solution K concentration (Fig. 3). Baghour et al. (2001) showed that increasing K fertilization resulted in reduced concen-trations of inorganic, organic, and total P. Nitrogen and P are highly mobile, and thus N

or P concentrations are lower in old leaves in N- or P-deficient plants (Mengel and Kirby, 1982). However, N and P concentrations are higher in the 14th leaf than the sixth leaf (Fig. 3), suggesting that Guzmania plants were not under N or P deficiency in the current experiment.

Leaf K concentration increased with increasing solution K concentration (Fig. 3). Except for the 6 mMK treatment, K

concen-trations were higher in the sixth leaf than the 10th or 14th leaves. New leaves in all Guzmania plants appeared healthy through-out this experiment. These clearly demon-strate that K is highly mobile in Guzmania. Similar to some palms (Broschat, 1997), the old leaves were a better indicator of Guzma-nia K status than the recently developed leaves. Because old leaves are a K reservoir, removal of K-deficient palm leaves can result in fewer symptom-free leaves and an accel-erated decline from K deficiency (Broschat, 1994).

Table 1. Effects of potassium concentration on new leaf number and dry weights of Guzmania lingulata Cherry. Potassium concn. (mM) New leaf number Shoot dry wt (g/plant) Root dry wt (g/plant) 0 14.7 6.9 2.0 2 15.3 8.0 2.4 4 15.7 8.7 2.2 6 14.7 7.4 2.3 Significance NS NS NS NS Nonsignificant.

Table 2. Effects of potassium concentration on leaf length and width, SPAD-502 reading, and numbers of leaves with yellow spots and chlorosis of Guzmania lingulata Cherry.

Potassium concn. (mM) Sixth leaf length (cm) Sixth leaf width (cm)

SPAD-502 reading _{Yellow spotted} leaf no.

Chlorotic leaf no. Sixth leaf 15th leaf

0 29.2 3.57 39.5 26.0 9.3 4.2 2 30.0 3.83 39.1 35.7 8.7 2.5 4 31.7 4.13 38.6 34.7 8.0 1.3 6 29.2 4.00 37.5 32.7 6.3 0.7 Significance NS L**Q** NS L**Q** L**Q* Q***

NS,*,**,***_{Nonsignificant or significant at P # 0.05, 0.01, or 0.001, respectively; L = linear; Q = quadratic.}

Fig. 1. Effect of potassium concentration on appearance of the 15th leaf of Guzmania lingulata ‘Cherry’. Table 3. Effects of potassium concentration on leaf tissue thickness, stomatal frequency and percentage

of opening stomata, and relative water content of Guzmania lingulata Cherry. Potassium concn. (mM) Thickness (0.01 mm) _Relative water content (%) Stomata Chlorenchyma Water storage tissue Total No. per mm2 Opening (%) 0 13.0 7.4 27.2 80.9 31.0 30.3 2 12.7 8.5 29.0 80.9 28.5 34.7 4 12.8 8.5 29.8 81.4 31.7 16.5 6 13.3 9.5 31.2 82.5 30.2 13.8 Significance NS L*Q* L***Q*** L**Q** NS L*

Our previous investigation on Guzmanias obtained from growers showed that leaf K concentration decreased gradually from leaf base (14.9 g
kg–1_{), middle (11.0 g
kg}–1_{), to tip}

(7.9 g
kg–1_{) in Guzmania ‘Cherry’, and that}

coincides with the K-deficiency symptoms expressed more on the tip and middle leaf portion. Similar to other monocots, a signif-icant higher K+_{concentration was also}

mea-sured at the growing leaf base than at the fully extended regions of corn (Mozafar, 1997), barley (Fricke and Flowers, 1998), and palm leaves (Broschat, 1997).

New leaf number and plant dry weights were not increasing at 6 mM K; however,

numbers of leaves with yellow spots and irregular chlorosis decreased at 6 mM K

(Tables 1 and 2). In the 6 mMK treatment,

leaf K concentration was15 g
kg–1_{on a dry}

weight basis in all leaves sampled (Fig. 3). These suggest that applying 6 mM K may be just adequate for vegetative growth of Guzmania.

As solution K concentration increased, leaf Ca and Mg concentrations decreased (Fig. 3). The pattern of increasing K concen-tration resulting in decreased leaf Ca and Mg concentrations is well documented (Mengel and Kirby, 1982; Sabreen and Saiga, 2004). Ca is relatively immobile in plant tissues and Mg is probably immobile in some plant species (Fricke et al., 1995). Thus, the 14th leaves had higher Ca and Mg concentrations than the 10th or the most recently developed leaf (Fig. 3).

Conclusions

Plant dry weight of Guzmania was unaf-fected under deficient conditions. The 0 K-treated plants exhibited yellow spots and patches of chlorosis in old leaves that had 2 to 8 g
kg–1_{K on a dry weight basis. Applying}

6 mMK increased leaf width, thickness, and

water content and reduced number of leaves with yellow spots or chlorosis. Recently developed leaves were appropriate for deter-mining N, P, Ca, and Mg concentrations, but older leaves are more suitable for analyzing the K status in Guzmania. Leaves of healthy Guzmania plants may contain 15 g
kg–1 _or

higher K on a dry weight basis.

Literature Cited

Arguero, O., D. Barranco, and M. Benlloch. 2006. Potassium starvation increases stomatal con-ductance in olive trees. HortScience 41:433– 436.

Baghour, M., E. Sanchez, J.M. Ruiz, and L. Romero. 2001. Metabolism and efficiency of phosphorus utilization during senescence in pepper plants: Response to nitrogenous and potassium fertil-ization. J. Plant Nutr. 24:1731–1743. Benzing, D.H. 2000. Bromeliaceae: Profile of an

adaptive radiation. Cambridge University Press, Cambridge, UK.

Broschat, T.K. 1994. Removing potassium-deficient leaves accelerates rate of decline in Phoenix roebelenii O’Brien. HortScience 29: 823.

Broschat, T.K. 1997. Nutrient distribution, dynam-ics, and sampling in coconut and canary island date palms. J. Amer. Soc. Hort. Sci. 122:884– 890.

Chase, A.R. and T.K. Broschat. 1991. Diseases and disorders of ornamentals palms. Amer. Phyto-pathol. Soc. Press, St. Paul, MN.

Fricke, W. and T.J. Flowers. 1998. Control of leaf cell elongation in barley. Generation rates of osmotic pressure and turgor, and growth-asso-ciated water potential gradients. Planta 206:53– 65.

Fricke, W., P.S. Hinde, R.A. Leigh, and A.D. Tomos. 1995. Vacuolar solutes in the upper epidermis of barley leaves. Planta 196:40– 49.

Fricke, W., R.A. Leigh, and A.D. Tomos. 1994. Concentrations of inorganic and organic sol-utes in extracts from individual epidermal, mesophyll and bundle-sheath cells of barley leaves. Planta 192:310–316.

Mengel, K. and E.A. Kirby. 1982. Principles of plant nutrition. 3rd ed. Intl. Potash Inst., Bern, Switzerland.

Mozafar, A. 1997. Distribution of nutrient ele-ments along the maize leaf: Alteration by iron deficiency. J. Plant Nutr. 20:999–1005. Nowak, E.J. and C.E. Martin. 1997. Physiological

and anatomical responses to water deficits in the CAM epiphyte Tillandsia ionantha (Bromeliaceae). Intl. J. Plant Sci. 158:818– 826.

Poole, R.T. and C.A. Conover. 1976. Nitrogen, phosphorus and potassium fertilization of bro-meliad, Aechmea fasciata Baker. HortScience 11:585–586.

Poole, R.T. and C.A. Conover. 1977. Nitrogen and potassium fertilization on Aglaonema commu-tatum Schott cvs. Fransher and Pseudobratea-tum. HortScience 12:570–571.

Richardson, B.A., M.J. Richardson, F.N. Scatena, and W.H. McDowell. 2000. Effects of nutrient availability and other elevational changes on bromeliad populations and their invertebrate communities in a humid tropical forest in Puerto Rico. J. Trop. Ecol. 16:167–188. Sabreen, S. and S. Saiga. 2004. Potassium level

suitable for screening high magnesium con-taining grass seedlings under solution culture. J. Plant Nutr. 27:1015–1027.

Shabala, S. 2003. Regulation of potassium trans-port in leaves: From molecular to tissue level. Ann. Bot. (Lond.) 92:627–634.

Shabala, S., O. Babourina, and I. Newman. 2000. Ion-specific mechanisms of osmoregulation in bean mesophyll cell. J. Expt. Bot. 51:1243– 1253.

Wang, Y.T. 2007. Potassium nutrition affects growth and flowering of Phalaenopsis grown in a bark mix or sphagnum moss substrate. HortScience . (in press).

Wright, R.D. 1986. The pour-through nutrient extraction procedure. HortScience 21:227– 229.

Xu, G., S. Wolf, and U. Kafkafi. 2002. Ammonium on potassium interaction in sweet pepper. J. Plant Nutr. 25:719–734.

Yeh, D.M., L. Lin, and C.J. Wright. 2000. Effects of mineral nutrient deficiencies on leaf development, visual symptoms and shoot-root ratio of Spathiphyllum. Scientia Hort. 86:223–233.

Fig. 2. Effect of potassium concentration on leaf anatomy of Guzmania lingulata ‘Cherry’.

Fig. 3. Effects of potassium concentration and leaf position on leaf macroelement concentration of Guzmania lingulata ‘Cherry’.

Breeding and Micropropagation of Aglaonema

D.M. Yeh

, W.J. Yang

, F.C. Chang

, M.C. Chung

, W.L. Chen

and H.W. Huang

1

_{Department of Horticulture, National Taiwan University, Taipei, Taiwan}

_{Institute of Plant and Microbial Biology, Academia Sinica, Taiwan}

Keywords: Aglaonema, flowering, chromosome, genetic relationship, micropropagation

Abstract

Breeding for Aglaonema (Araceae) cultivars with beautiful foliar variegation

and color has long been the prevailing goal. The present works studied on regulation

of flowering, chromosome number and genetic relationship to facilitate

hybridization. Plants flower within 23 to 48 weeks, depending on the cultivar,

following a single spray with 250 ppm gibberellic acid (GA

). RAPD analysis on 61

accessions showed that Aglaonema genotypes are highly diverged and could be

clustered into seven groups. Cultivars ‘Curtisii’ and ‘Galaxy’ are diploid (2n = 40),

‘Pride of Sumatra’ and ‘Chalit’s Fantasy’ have 50 and 60 chromosomes,

respectively. At least eight dominant alleles each with distinct pattern have been

identified. Tissue culture is preferable for rapid multiplication of healthy plants. The

inflorescence was an alternative source of explants to reduce endogenous microbial

contamination, and the suggested cultural medium was half-strength MS basal

medium with 5 to 10 µM Dicamba and 10 µM TDZ for direct shooting. After

transferring to a shaded greenhouse, plants under 130 μmol.m

.s

during ex vitro

acclimatization had higher dry weight than those under 80 or 200 μmol.m

.s

.

INTRODUCTION

Aglaonema (Araceae) contains many cultivars that are important tropical foliage

plants due to their tolerance of drought and low light and low relative humidity levels

encountered under interior conditions (Chen et al., 2002). Breeding for cultivars with

beautiful foliar variegation and color has long been the prevailing goal. Control of

flowering by application of gibberellic acid sprays (Henny, 1983) and development of

pollination techniques (Henny, 1988) led to the production of new cultivars. Knowledge

of inheritance of foliar variegation (Henny, 1986) and genetic relationships of species and

cultivars (Chen et al., 2004) make planning crosses easier. A part of this paper provides

additional information on flowering time, inheritance of foliar variegation, and

chromosome and genetic analysis of Aglaonema species and cultivars.

Commercial Aglaonema production almost exclusively starts from cuttings.

Cutting propagation, however, may transmit pathogens from stock plants to cuttings.

Tissue culture is preferable for rapid multiplication of healthy plants. Tissue culture has

not been particularly successful with Aglaonema (Chen et al., 2003), largely due to

endogenous microbial contamination. Reduced occurrence of contamination and

browning in axillary bud explants excised from the stock plants of Aglaonema Schott

‘White Tip’ that had not been watered for 2 months (Chen and Yeh, 2007). However,

drought stress might have detrimental effects on mother plants. The present works were to

explore the possibility of using female flowers as explants for multiplication, to compare

explants’ growth using temporary immersion system (TIS) and semi-solid cultural

system, and to determine the effects of photosynthetic photon flux (PPF) during ex vitro

acclimatization on subsequent growth of micropropagated A. ‘White Tip’.

REGULATION OF FLOWERING

To regulate flowering for pollination and hybridization, effects of temperature

and/or GA

on flowering of Aglaonemas were studied under phytotron conditions. A.

commutatum ‘Emerald Beauty’ increased flowering and number of inflorescences, after a

single spray of 250 ppm GA

in late November under 30/25 and 25/20°C conditions for 7

weeks followed by transferring to 18-22°C greenhouse conditions (Table 1). None of the

93

Proc. IC on Qual. Manag. Supply Chains of Ornamentals

Eds.: S. Kanlayanarat et al.

plants without GA

treatment showed any sign of flowering when the experiment was

terminated after 185 days. Similar flowering responses to temperature and GA

were

observed in Aglaonema commutatum ‘Pseudobracteatum’, Aglaonema ‘Silver Queen’,

and A. commutatum ‘Elegans’ (Chen and Yeh, 2003). These results are consistent with

Henny (2000) showing that GA

treatment induces flowering of Aglaonema and many

other ornamental aroids. Under a 60% shaded greenhouse at 18 to 32°C, Aglaonema

species and cultivars flower within 23 to 48 weeks following a single spray with 250 ppm

GA

(Table 2).

INHERITANCE OF FOLIAR VARIEGATION

The foliar variegation patterns were found to be governed by a single-locus,

multiple-allelic system (Henny, 1986). Each distinct pattern is controlled by separate

dominant alleles. These alleles are codominant, allowing for the expression of two

variegation patterns in the same plants. At least eight dominant alleles each with distinct

pattern have been identified (Chang, 2005; Henny, 1986).

CHROMOSOME NUMBER

The chromosome number varies from 2n = 42 to 60 or 120 (Nicolson, 1969)

depending on species. Our investigation showed that cultivars ‘Curtisii’ and ‘Galaxy’ are

diploid (2n = 40), while ‘Pride of Sumatra’ and ‘Chalit’s Fantasy’ have 50 and 60

chromosomes, respectively (Fig. 1). A. brevispathum Jervis, A. cochinchinense Engl. and

‘Silver Bay’ also have 40 chromosomes. Our observation reveal that the species and

cultivars, with 40 chromosomes as mentioned above, could produce pollens and set fruits,

while cultivars ‘Chalit’s Fantasy’ and ‘Pride of Sumatra’ failed to do so.

GENETIC RELATIONSHIP

The breeding of Aglaonema has been popular and caused the needs of genetic

analysis. Due to highly interspecific hybridization, molecular characteristics are much

more accessible than morphological investigation in studying genetic relationship. Chen

et al. (2004) analyzed 54 Aglaonema species and cultivars by AFLP (amplification

fragment length polymorphism) and showed that A. commutatum, A. crispum and A.

nitidum derived cultivars clustered in the same group with similarity higher than 0.84.

The revealed genetic relationship was in agreement with the A. commutatum was a

species putatively derived from A. nitidum, A. crispum, A. marantifolium or A.

philippense Engl., and A. simplex through introgressive hybridization (Jervis, 1980;

Nicolson, 1969).

Chang (2005) analyzed the genetic relationship among the 61 Aglaonema

accessions through RAPD (random amplified polymorphic DNA). The result indicated

that Aglaonema genotypes are highly diverted and can be clustered into seven groups.

The incongruity between group I or II and the last five groups (III, IV, V, VI, and VII) are

very high. However, A. brevispathum (Engl.) Jervis f. immaculatum (III), A. simplex (V),

and A. rotundum×A. simplex (V) were the exceptions which could be crossed to group I

as pollen parent, and thus, conferred the incongruity between groups and severed as

bridge cultivars. A. pumilum (IV), rotundum (V), and pictum (VI) are three species with

less complicated genetic background and much distant from others. A. costatum N.E. Br.

var. costatum f. foxii (Engl.) Jervis ‘Foxii Grande’ and A. brevispathum clustered to be

group III. Group I could be divided into three subgroups, IA, IB, and IC, respectively. A.

rotundum×A. simplex (V) was suggested as the paternal materials to transmit red pigment

to other cultivars.

TEMPORARY IMMERSION SYSTEM (TIS) VS. SEMI-SOLID MEDIUM

Using TIS may increase the rate of multiplication, plant growth, and reduce cost of

in vitro culture (Meira, 2000). The 0.5-cm node sections of ‘White Tip’, with 1-2 axillary

buds for each section, were used as explants. More fresh weight and shoot number was

measured in TIS than in semi-solid system (Table 3). More growth was measured in

94

explants with 1/2 MS macroelement strength for TIS, as compared with MS for

semi-solid system (Chen, 2006).

INFLORESCENCES AS EXPLANTS FOR MICROPROPAGATION

Female flowers of ‘White Tip’ and ‘Emerald Beauty’ were sectioned, sterilized

with NaOCl 0.5% or 1.0% for 5 to 15 minutes. Neither contamination nor browning

occurred during in vitro culture period. Direct shooting was induced when cultured on1/2

MS basal medium with 5 to 10 µM Dicamba and 10 µM TDZ (Fig. 2). Using

inflorescences as explants offers great promise since several Aglaonema plants could be

propagated from a single inflorescence without significant damage to the mother plants.

EX VITRO ROOTING AND PPF DURING EX VITRO ACCLIMATIZATION

Indole-3-butytric acid (IBA) at 9.8 or 19.7 mM applied to the base of the

microcuttings resulted in 100% ex vitro rooting and the longest roots (Chen and Yeh,

2007). Micropropagated plants were transplanted to a soilless mix and placed in a growth

room at 25 ± 1°C under cool-white fluorescent light providing 16 h daily photosynthetic

photon flux of 80, 130 or 200 μmol.m

.s

. After having been acclimatized for 70 days in

the growth room, the plantlets were then transferred to a shaded greenhouse for 90 days

and their growth was measured. Plantlets under 130 μmol.m

.s

had subsequent greater

growth (Table 4). Measurements of Fv/Fm value, photosynthetic rate indicated that

plantlets under 200 μmol.m

.s

exhibited photo-inhibition while photosynthetic rate

under 80 μmol.m

.s

was lower than 130 μmol.m

.s

(Chu and Yeh, 2006).

ACKNOWLEDGEMENTS

Financial support for the breeding projects on Aglaonema is gratefully

acknowledged from the Council of Agriculture of Taiwan.

Literature Cited

Chang, F.C. 2005. Flowering, pollination, inheritance of foliar variegation and phylogeny

analysis in Aglaonema. Master's thesis, Dept. of Hort., National Taiwan Univ.

Chen, J., Henny, R.J. and McConnell, D.B. 2002. Development of new foliage plant

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Tables

Table 1. Effects of temperature and 250 ppm GA

on flowering of Aglaonema

commutatum ‘Emerald Beauty’.

Treatment

Mean days to

Day/night

temp.

(°C)

250

ppm

GA

Lowest

flowering

node

Mean

no.

inflorescences

Visible

spathe

unfolding

Spathe

Female

flowers

discolored

Male

flowers

wilted

30/25 + 10.7a

2.5a 156.2c

158.4c

162.7c

167.5c

-

---

--- ---

--- ---

---

25/20 + 11.0a 2.0b 160.0b

164.6b

169.0b

171.8b

- --- --- ---

--- ---

---

20/15

+

9.4b

1.0c

180.6a

185.1a

189.2a

194.9a

- --- --- ---

--- ---

---

z

_{Mean separation within columns by LSD at P≤0.05.}

_{Still not flowered at the end of experiment}

Table 2. Effects of 250 ppm GA

treatment on flowering of Aglaonema species or

cultivars.

Days to flowering (weeks)

Flowering (month)

Species or cultivar

Year 2002

Year 2003

Year 2003 Year 2004

A. simplex

29-30 28-29 6 5-6

A. ‘Angel Delight’

45-46 27-28

5-6,

9-10

5-6

A. ‘Goden Bay’

24-25 28-29 8,

11-12 6

A. cohinchinenes

42-43 25-26 9 5-6

A. pictum ‘Tricolor’

33-34 23-24 7

4-5,

7-10

A. ‘Rembrandt’

29-30 28-29 5-6,

11

5-7

A. ‘White Tip’

32-33

31-32

4-12

4-6, 8-9

A. crispum ‘Fantasy’ 34-35

28-29

4,

6-12

5-8

A. ‘Silver Bay’

46-47

28-29

4-12

4-7, 9-11

A. ‘King of Siam’

32-33

30-31

4-7, 10

4, 6

A. ‘Emerald Beauty’

32-33

28-29

4-10, 12

5-7

A. ‘Galaxy’

46-47

30-31

4, 6-12

6, 9-10

A. nitidum ‘Curtisii’ 32-33

31-32

4-12

4-12

A. pictum ‘Bicolor’

34-35 33-34 7-8 7,

9

A. commutatum ‘Pseudobracteatum’

32-33 32 5-8 7

A. commutatum ‘Elegans’ 33-34

28-29

5-8

5-7

A. ‘Chalit’s Fantasy’

26-27

28-29

4-6, 9-10

5-6

A. ‘Sithiporn Green’

23-24

26-27

4, 7, 10

5, 8-9

A. ‘Marry Ann’

46-47

28-29

5, 9-12

5-6, 9

A. ‘Manila Whirl’

32-33 30-31 6-7,

10

5-6

96

Table 3. Effect of strength of MS macroelements on growth of micropropagated

Aglaonema ‘White Tip’ in temporary immersion system (TIS) and semi-solid culture.

Strength of MS

macroelements

Plant height

(cm)

Fresh weight

(g)

Shoot number

Root number

TIS

1/2

2.2±0.7 a

0.7±0.2 a

5.1±1.3 a

0.9±0.3 a

1

1.7±0.5 b

0.6±0.2 ab

4.3±0.9 ab

0.8±0.4 a

2

0.9±0.3 cd

0.5±0.1 bc

4.0±0.7 b

1.1±0.3 a

Semi-solid medium

1/2

0.9±0.2 d

0.4±0.1 c

3.6±0.5 b

0.8±0.4 a

1

1.0±0.4 cd

0.4±0.1 c

4.3±0.8 ab

0.8±0.4 a

2

1.4±0.5 bc

0.4±0.1 c

3.5±0.5 b

1.1±0.5 a

Significance

MS strength (M)

***

**

***

NS

System (S)

***

***

*

NS

M × S

***

NS

NS

NS

z

_{Means separation within columns by LSD test at P≤0.05.}

NS, *, **, ***

_{Non-significant, or significant of at P≤0.05, 0.01 and 0.001, respectively.}

Table 4. Effects of photosynthetic photon flux (PPF) during ex vitro acclimatization on

subsequent growth of micropropagated Aglaonema ‘White Tip’.

Dry wt. (mg/plant)

PPF

(μmol/m

/s)

No. of

leaves

No. of

roots

No. of

shoots

Leaf area

(cm

)

Shoot Root

80

7.8 a

18.0 ab

3.2 b

43.7 ab

330.6 ab

113.0 b

130

7.6 a

23.6 a

5.4 a

67.1 a

605.5 a

182.2 a

200

6.8 a

12.6 b

3.8 b

36.7 b

297.7 b

50.3 b

z

_{Mean separation within columns by LSD at P≤0.05.}

Figures

Fig. 1. Chromosomes of Aglaonema cultivars ‘Curtisii’, ‘Galaxy’, ‘Pride of Sumatra’,

and ‘Chalit’s Fantasy’.

Fig. 2. Shoot multiplication from female flowers of Aglaonema ‘White Tip’ cultured in

1/2 MS basal medium with 10 µM Dicamba and 10 µM TDZ.