Microbiology

Seedling characteristics of Erythrina suberosa Roxb. are described. Its seeds were collected from a tree growing in
the Campus of University of Karachi and germinated without any dormancy breaking treatment in pots filled with
garden sandy loam soil maintained at 75% MWHC. Maximum germination was 50% achieved within a week. The
seedlings were studied when they were 20-day (younger) and 50-day old (elder). The seedling was of Phanerocotylar –
Epigeal Reserve type. The major allocation of biomass in 20-day seedlings was in leaves and in 50-day seedlings in
leaves and hypocotylar stem. The major growth spur in seedlings during the 30-day period from 20th to 50th day was in
hypocotylar and epicotylar stem and root. Tap root had profuse laterals. Numerous root nodules 3.5 - 5mm in diameter
were present generally on the main root. Cotyledons were large, green fleshy –food laden, concave inside and convex
outside with no visible venation. They were wholly consumed within 50 days after germination. Internode size reduced
from base to apex regularly. The hypocotyl was green, shining and provided with little prickles. Epicotyl is hairy. The
primary leaves were simple opposite, erect, glaucous dorsally and pubescent ventrally. The subsequent leaves were
pinnately trifoliate (ternate) with three leaflets. Each leaf had small, green and linear-lanceolate stipules. Glanduliform
stiples present. Epicotyl was longer than hypocotyl. The total leaf area of elder seedlings was (209.08 ± 15.71 cm2) -1.6
times to that in the younger seedlings. The leaf venation was pinnate camptodromous (festooned brachidodromous)
type. Vein-endings were straight or curved and unbranched. Two types of trichomes were seen – branched trichomes
and capitate glandular trichomes. The leaves were hypo-amphistomatic – paucistomatic dorsally and multistomatic
ventrally. The cotyledonary stomata were of paracytic type but on ventral surface of leaf five types of stomata (sensu
Prabhakar, 2004) - paracytic, anisocytic, anisotricytic, anomocytic and staurocytic were present; paracytic being the
most abundant and staurocytic the least. Stomata on dorsal side of leaf were rare and of paracytic type only along the
main vein. Both surfaces of leaf had capitate glandular trichomes (6.16 per mm2 on ventral surface and much infrequent
on the dorsal side). The number of stomata on ventral surface of the leaf tended to be normally-distributed amongst the
100 sampling fields of the microscope vision (each of 0.10174 mm2) at 45 x 10 X magnification. The mean density of
stomata per mm2 was 110.28 ± 2.07 (68.80 – 157.3; CV: 18.73%).

Newcastle disease (ND), Infectious bursal disease (IBD) and mycoplasmosis are common respiratory
diseases of poultry affecting several billion rupees business in Pakistan. Prevalence of these diseases demands specific
strategies to control their occurrence. Efforts were made to develop Dot-ELISA for detection of antibodies against
NDV, IBD and Mycoplasma gallisepticum (MG). Dot-ELISA was performed on the sera samples collected from sick
birds showing symptoms of ND, IBD and Mycoplasmosis. Antibodies were detected by dot-ELISA against NDV,
IBDV and MG. Study showed that birds were highly exposed to MG in our region. Antibodies were detected against
NDV, IBDV and MG in 37.2%, 32.1% and 54.7% infected birds, respectively. Present study also showed that the
birds possessed antibodies against more than one pathogen tested: 5.1% of the infected birds possessed antibodies
against NDV and IBDV; 9.5% against NDV and MG; and 11.7% against IBDV and MG. Data also showed that 2.9%
of the infected birds were exposed to all the three pathogens that were tested. Antibodies were also detected in the sera
obtained from healthy birds against all these three pathogens. Around 9.5%, 8.4% and 15.5% sera were found to
contain antibodies against NDV, IBDV and MG, respectively. Present study also showed that the prevalence of coinfections
are 1.9% (NDV and IBDV), 3% (NDV and MG) and 3.3% (IBDV and MG), respectively. Dot-ELISA using
specific antigens from pathogens is very specific, highly sensitive, less time consuming with little false result. A
diagnostic kit can be prepared for large number of pathogens; this combine approach of several antigens on a single
strip can play an important role in the diagnosis of poultry disease at early stage, and help in controlling infectious
diseases in poultry sector in Pakistan.

Seedling characteristics of Bauhinia racemosa Lamk. are described. The seedling was of Phanerocotylar – Epigeal Reserve type. The total leaf area per seedling increased exponentially with age with relatively larger rate of leaf-area-increment by the 40th day of seedling age. The major allocation of biomass in 60-day old seedlings was in leaves - 49.65% of the seedling total dry mass (190.77 ± 34.47 mg). Tap root had profuse laterals. Cotyledons were obovate large, green fleshy and food laden. They were wholly consumed within around 50 days after emergence. From base to apex, first internode was the largest one and internodal size of subsequent internodes reduced to nearly half of the first internode. The hypocotyl was pale green, terete. Epicotyl hairy. The primary leaves were simple alternate, bilobed, pubescent ventrally. Each leaf had small, green and linear-lanceolate stipule. Leaf apex obcordate and leaf base cordate – embayed in sinus. Midrib extension (≤ 1mm) in the apical notch. Leaves and cotyledons showed photonastic movement. Epicotyl was longer than hypocotyl but hypocotyl was thicker (generally twice) than epicotyl. The total leaf area of 60-day old seedlings was (2256.57 ± 193.74 mm2). Cotyledons were 5-6(7)-nerved and leaves were 9-nerved. The cotyledonary and foliar venation was brachidodromous type. The cotyledons and leaves were amphistomatic. The number of subsidiary cells associated with different types of stomata varied from two to eight. Paracytic, anisocytic, anisotricytic, anomocytic and staurocytic types of stomata were found on leaves and cotyledons (sensu Prabhakar, 2004). Abnormal stomatal types included a staurocytic type with two abutting pores and other  included a group of contiguous anisotricytic type of stomata with variously shaped subsidiaries and the one anisotricytic stomata with two abutting pores. The epicotylar stomata were of paracytic type. Stomata were comparatively smaller on leaf (c 13 μm) than on the cotyledons (c 18 μm).  Seedling characteristics are compared with available data for other Bauhinia species.

number of insects. During a survey, 10 isolates of Bacillus thuringiensis were isolated from
rhizosphere of okra, brinjal, tomato, cotton, cabbage, onion and water melon crops cultivated in
Karachi, Thatta, Hyderabad and Nawabshah. These isolates were evaluated for their nematicidal
potential under laboratory and green house experiments. In laboratory studies, eggs and Juveniles
were exposed to different BT isolates at 50% concentration of cell free filtrate for different time
intervals. The cell free filtrate not only inhibited the hatching of eggs but also killed the second
stage juveniles at different time intervals. In green house studies seed treatment of okra
(Abelmoschus esculentus (L.) Moench var Arka anamika) and Mung bean (Vigna radiata [L.]
Wilczek cv.MN-95) with cell suspension of BT isolates improved plant growth and reduced
number of galls, Egg masses, Eggs/egg mass, Nematode population /g roots and Nematode
population /200g soil as compared to non-treated control.