Relative role of male and female Hyalomma anatolicum anatolicum ticks in Theileria transmission

The relative role of male and female Hyalomma anatolicum anatolicum ticks in the epidemiology of Theileria transmission was studied by detecting Theileria sporozoites in the dissected salivary glands of 568 ticks by the methyl green pyronin staining method. Detailed frequency distribution of Theileria-positive acini in the salivary glands of the 264 (46.48%) positive ticks from a field collection in Haryana indicated that the number of infected salivary acini per positive tick was greater in females than in males. This suggests that female ticks have a more important role in Theileria transmission than male ticks. This finding assumes greater significance in the light of the observation that the natural male:female ratio is also in favour of female ticks.     

Ultrasonographic evaluation of the omasum in cows and buffaloes.

The study was conducted to establish the ultrasonographic features of the healthy and impacted omasum in cows and buffaloes. Scanning was done using a 3.5 MHz microconvex transducer. In healthy buffaloes, the omasum could be scanned at the eighth to ninth intercostal space as a round or oval structure having thick echogenic wall with echogenic leaves. Gradual slow movements of omasal leaves could also be seen in real-time B-mode. The omasum appeared to be very clear, large, and close to the transducer at the start of the omasal contraction, and as the contraction progressed the omasum retracted away from the transducer and became very small. In healthy cows the omasum was seen as a crescent-shaped structure with an echogenic wall. The contents of the omasum or omasal leaves could not be visualized. Omasal contractility was not as prominent as in buffaloes. In buffaloes, the impacted omasum appeared amotile, the omasal leaves were not visible, and the omasum as a whole gave a prominent distal acoustic shadow. In cows, the impaction could be diagnosed based on amotile omasum covering a large area on the right side. Ultrasonography was found to be helpful in subjective assessment of omasal impaction but could not aid in diagnosing the severity of impaction.     

Changes in plant water status of Maize (Zea mays L.) with ontogeny

Summary Irrigations scheduled on plant water status ignore the effect of ontogeny on plant water status. Leaf xylem water potential (XWP) of maize sown on three dates in a sandy loam soil was measured under the same environment for evaluating the effect of ontogeny on plant water status. Minimum XWP (measured between 13.00-14.30 h) of the youngest crop was the highest during two crop seasons and the differences in XWP of the youngest and the oldest maize plants ranged from 0.25 to 0.65 MPa during the season. Maximum XWP (measured before dawn) of the youngest crop was nearly 0.1 MPa higher than that of the oldest crop. Diurnal variation in XWP was lowest in the youngest crop. The results highlight the need of ontogeny dependent critical values of plant water status for scheduling irrigation.     

In vitro germination of walnut (Juglans regia L.) embryos

The present studies were undertaken with a view to standardize the medium and culture conditions for embryo culture of five cultivars of walnut viz., ACO 38853, Netar Akhrot, Gobind, Solding Selection and Blackmore. Embryos from mature fruits were aseptically excised and cultured on MS medium supplemented with different combinations of BAP, kinetin and GA₃. Best performing medium was MS with 0.5 mg l⁻¹ kinetin, 0.5 mg l⁻¹ BAP and 2 mg l⁻¹ GA₃ yielding 66.6% germination in Netar Akhrot after 12 days of culturing. Percent germination of excised embryos was higher when GA₃ and cold treatments were simultaneously applied as compared to those when applied separately. Netar Akhrot was found to be the best responding cultivar, which had a range of 25–66.6% embryo germination under different culture conditions. Plantlets with shoots and roots have been obtained in Netar Akhrot and ACO38853 and are transferred to soil after hardening.