Effect of kinetin on water relations,photosynthesis, respiration and chlorophyll and nucleic acid contents of wheat (Triticum aestivum L.) grown under salinity

The effect of kinetin (10 g m^-3) presowing seed soaking treatment on water relations, chlorophyll (Chl) and nucleic acid contents, and photosynthetic and respiration rates in wheat (Triticum aestivum L.) grown in a greenhouse under three salinity levels (i.e. 0,6 and 9 dS m^-1 ECe) was studied. Relative water content and osmotic potential showed a progressive decline with increase in the salinity but there was an increase in chlorophyll (a+b) content in the leaves. Salinity decreased RNA content and net photosynthetic and respiration rates. Seed soaking either in water or kinetin enhanced the relative water content of leaves but reduced osmotic potential under both saline and non-saline conditions.     

Ultrasonography for detection of early pregnancy following embryo transfer in unknown breed of Bos indicus cows

Real time, B mode ultrasound was used from Days 18 to 64 to detect and monitor the conceptus in 30 unknown breeds of Bos indicus recipients following embryo transfer. The embryonic vesicle was first visible within the uterus between Days 18 and 20 (mean +/- SD 18.5 +/- 0.7d) d). The embryo proper was detected at Day 19.5 +/- 0.7. The heartbeats were detected at Day 22.6 +/- 0.9. The average day of first detection of the allantois, the C - shaped embryo and the amnion was 23.1 +/- 0.8, 23.8 +/- 1.4 and 25.1 +/- 1.4 d, respectively. The fore limb, the limb buds, the spinal cord and the optic area were observed on Days 32.7 +/- 1.3, 32.9 +/- 1.3, 33.0 +/- 1.5 and 33.6 +/- 1.4, respectively. Fetal movements could be detected at Day 50.7 +/- 1.0. Ribs and vertebrae were detected on Day 60.9 +/- 1.7. The mean length of the embryo proper was 4.5 +/- 0.8 mm. on Day 19. At Day 60 it was 52.5 +/- 7.0 mm. The growth of the embryo proper increased steadily until Day 39, growing rapidly thereafter. Embryonic death was detected in one recipient on Day 32. The echongenic area started increasing and recipient appeared in estrus on Day 40. Sixteen recipients exhibited estrus on Days 22 to 24. An increase in intrauterine fluid was observed on Days 18 to 24.     

Ammonia attracts the haematophagous bug Triatoma infestans : behavioural and neurophysiological data on nymphs

1) Nymphs of the haematophagous bug Triatoma infestans (Heteroptera: Reduviidae) are attracted to volatiles from their own faeces on a servosphere. 2) Biological substrates attractive to triatomines release NH₃: wetted triatomine faecal papers release NH₃ at 256 ppb NH₃ from a 60-g source and stale rabbit urine at 394 ppb from 200 ml. Ammonia released from aqueous NH₃ also attracts bugs at doses of 3 ppb and 17 ppb on the servosphere. 3) Bugs typically show negative anemotaxis in a stimulus-free air-stream on the servosphere. At onset of stimulation with ammonia from either biological substrates or aqueous NH₃ the bugs stop, move their antennae, turn and walk upwind, i.e. odour-mediated anemotaxis. 4) At lower NH₃ doses a latency in attraction is recorded, but this latency disappears when the relative humidity of the stimulus delivery air-stream is dropped from 90 to 35%. 5) Electrophysiological recordings from single olfactory sensilla on antennae of Triatoma nymphs reveal two different types of NH₃-excited receptors, both within grooved-peg sensilla. The responses of one of these receptor cells to NH₃ has been studied in detail and shows that the action potential discharge rate is dose-dependent over the range 2–200 ppb. 6) The amplitudes of electroantennograms recorded from Triatoma nymphs to NH₃ are dose dependent over the range 5–550 ppb. Accepted: 16 January 1997