M. A. Miah
Dept. of Entomology, Patuakhali Science & Technology University, Dumki, Patuakhali-8602, Bangladesh
M R Ali
Dept. of Entomology, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh
M. Z. Hassan
Dept. of Agronomy, PSTU, Dumki, Patuakhali-8602, Bangladesh
G. Saha
Dept. of Agronomy, PSTU, Dumki, Patuakhali-8602, Bangladesh
Mungbean, Resistance and Callosobruchus chinensis.
The experiment was carried out in storage condition in the laboratory under the Department of Entomology, Sher-e-Bangla Agricultural University (SAU), Dhaka, Bangladesh
Pest Management
A total of 9 mungbean varieties i.e. BU Mug-1, BU Mug-2, BARI Mug-2, BARI Mug-3, BARI Mug-4, BARI Mug-5, BARI Mug-6, BINA Mug-1 and Barisal local were used in the present study. The tested mungbean varieties were collected from Bangladesh Agricultural Research Institute (BARI), Gazipur, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh Institute of Nuclear Agriculture (BINA), Mymensingh and their characteristics are presented in Table 1. Prior to testing, all their varieties were sun dried to remove pre-infestation. Test insects (Pulse beetles, C. chinensis) used in the present investigation obtained from the stock cultures in the laboratory of the Dept. of Entomology, SAU. Stock culture was maintained on mungbean seeds in plastic jars covered with markin cloth in the same laboratory. One hundred pairs of C. chinensis were introduced into a plastic container (12 cm dia. ´ 14 cm height) containing 200 gm of infested seeds. The mouth of the containers was covered with perforated plastic lids. The insects were allowed to mate and lay eggs for 24 hours. After 24 hours, sieving was done to separate the adult beetles. The mungbean seeds with eggs left on the sieve were kept for adult emergence. One-day-old adults were used for study. The rearing procedure was repeated in different batches to ensure continuous supply of the adults.
Male and female beetles were sorted out under simple microscope by their antennal characteristics, size and shape of the body. Then used for this experiment.
Tested mungbean varieties were screened for resistance against C. chinensis in both ‘free choice’ and ‘no-choice’ tests under laboratory conditions.
In free-choice test, all tested mungbean varieties were subjected to the attack of C. chinensis freely, following the method described by Raina (1971) and Dahms (1972). Twenty grams of de-infested healthy seeds of each mungbean variety were taken in individual plastic pot (6 cm dia. x 9 cm height). The seed containing pots were placed randomly at equal distances around a central circle in the mosquito netted topped tin cage (60 cm dia. x 90 cm height). Then 150 pairs of one-day-old (0-24 hours) healthy adults of C. chinensis from the stock culture were taken in a petridish (90 mm dia.) and placed it in the centre of the cage. The lids of all plastic pots containing mungbean seeds and petridishes were removed and covered the cage quickly with mosquito net tightly. The insects were allowed to remain there for the purpose of oviposition. After three days (72 hours) of release, both dead and alive insects were removed from the plastic pots. The number of eggs laid on the seeds in each pot was then recorded by visually. The pots with the lids were then stored under room conditions. The developmental stages were also observed and the data were recorded. The number of adults emerged and the weight of the grains were recorded after about 30 days (complete emergence of adult from the laid eggs). For recording data, 20 seeds for each variety of mungbean were randomly collected from each variety/pot.
In this test C. chinensis were allowed to enter only one seed variety. Twenty grams of de-infested healthy seeds of each variety were taken in individual plastic pots (6 cm dia. x 9 cm height). Then 5 pairs of one-day-old healthy adults of C. chinensis from the stock culture were released in each pot and covered with lids. After three days (72 hours) allowance for oviposition, both dead and alive insects were removed from the pots and then the same procedure was followed as in the free-choice test. Data were recorded as previous parameters.
Initial weight (Before setting the experiment) and the final weight (After complete emergence of adults from the laid eggs) of the grains were recorded separately for each variety. Seed damage was expressed as the percentage and the percentage of seed damage was also graded as level of resistance. The experimental data were analyzed by ANOVA-1 in Completely Randomized Design (CRD) with three replications and the means were separated by Duncan’s Multiple Range Test (DMRT).
Bangladesh J. Seed Sci. & Tech. 14 (1 &2): 201-207 (2010), ISSN 1029 - 8800
Journal