M.K. Biswas*
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, China, 430070
R. Islam
Department of Botany University of Rajshahi, Bangladesh
M. Hossain
Department of Botany University of Rajshahi, Bangladesh
Micropropagation, Strawberry, Genetic parameters, Path coefficient
Crop-Soil-Water Management
Establishment of aseptic explants: Runner tips were collected from nursery grown stock plants of three strawberry clones (pbgel-01, pbgel-02 and pbgel-03 developed by Plant Breeding and Gene Engineering lab, Department of Botany University of Rajshahi, Bangladesh) and were washed with Tween 80. Afterwards, explants were rinsed several times with sterile distilled water. Surface sterilization was done inside the laminar air flow cabinet by dipping the explants in 0.1% HgCl2 solution (w/v) for five minuets. Sterile runner tips’ having terminal buds (3-4 mm) were dissected and cultured in MS medium containing 3% sucrose, 0.8% agar. The pH was adjusted to 5.8 before adding agar and autoclaved. The cultures were incubated in a growth chamber under 16/8 h light/dark cycle at 25±2°C. The aseptic shoots that were obtained after two weeks of cultures were used as a source of explants for subsequent experiments.
Selection of best medium for mass propagation: For mass propagation media selection, aseptic proliferated shoots were cultured on MS media having NAA, BA and Kin used either singly or in combinations. Shoots number, harvestable shoots and the frequency of responded proliferating shoots were recorded. Microshoots were rooted on the half strength of MS medium without growth regulators.
Acclimatization and Field performance of micro propagated plantlets: Three-week-old rooted shoots were removed from the culture tubes, thoroughly washed to remove agar traces and then transferred to plastic pot containing garden soil and cowdang (3:1 v/v). Plants were watered immediately after planting with sprayer and kept under shade covered with transparent plastic sheets made dome to maintain moisture. After one week dome was removed and plants were fully exposed on sunlight.
The transplanted strawberry micro propagated plantlets were evaluated in the experimental field of Plant Breeding and Gene Engineering lab, Department of Botany University of Rajshahi, Bangladesh during 2001-2004. Sixty days old tissue culture derived plantlets and thirty days old runner derived plantlets were sown in field. The experiment was laid out in the randomized complete block design with three replications. Plantlets were planted at 40 cm × 35 cm distance on 50 cm wide and 350 cm long raised bed. The soil of the experimental plots was specially amended with cowdong and coarse sand (1:1 v/v). Urea-TSP-MP was applied at the rate 75-60-75 kg/ha. The entire dose of TSP, MP and 50% urea was applied as top dressing into two equal installments at 30 and 60 days after planting. Intercultural operations such as earthing up, weeding and mulching were done as required. Field experiments were repeated three times (October-2001 to February-2002; October-2002 to February-2003; October-2003 to February-2004). Nine plants were selected at random from each replication and data were subjected as plant height (PH), no of leaf (NL), canopy size (CZ), no of runner (NR), no of crown (NC), no of fruit per plant (NF) and average fruit weight per fruit (AFW). Most of the traits were measured at three months after plantation where as the NF and AFW were measured at after four months after plantation.
Data analysis Data were analyzed by some biometrical techniques developed by Mather (1949), Hayman (1958), De-wey and Lu (1959) and Allard (1960). Means were separated with Duncan’s multiple range test (P<0.05) where appropriate. Correlation between seven agronomic traits and some genetic parameters were also estimated. All the statistical analysis was performed by using MS excel and MSTAT-C and SAS software.
Journal of Agricultural Technology 4(1): 167-182.
Journal