Effect of potassium nutrition on frost damage and yield of potato plants on alluvial soils of the Punjab (India)

Summary Field experiments were conducted during 1974 and 1975 on 14 alluvial soils, varying in available K from 56 to 158 ppm, at Jullundur-Punjab (India) to study the effect of K nutrition on frost damage to potato crops. Frost damage was inversely related to the available K content of the soils and the K concentration of the potato leaves. K fertilization significantly reduced the frost damage and increased tuber yields in soils containing less than 114 ppm available K. Frost damage was significantly related to potato response to K application and negatively correlated to tuber yield.     

Restricted sleep regime in rhesus monkeys: differential effect of one night's sleep loss and selective REM deprivation.

The differential effect of either one night's total sleep deprivation (TSD) or of selective REM deprivation (REMD) was examined on post-deprivation daytime EEG patterns with respect to control, in the same group of rhesus monkeys. TSD resulted in significantly decreased wakefulness and increased amounts of NREM and REM on the first day following TSD. In contrast, highly significant REM elevation without alteration of other EEG states occurred for 3 days after REMD. Post-deprivation behavioural and photic-induced neural changes were minor. The results obtained after sleep deprivation in simians are comparable with similar findings in human subjects.     

Plant and Soil Nematodes: Societal Impact and Focus for the Future.

Plant and soil nematodes significandy impact our lives. Therefore, we must understand and manage these complex organisms so that we may continue to develop and sustain our food production systems, our natural resources, our environment, and our quality of life. This publication looks specifically at soil and plant nematology. First, the societal impact of nematodes and benefits of nematology research are briefly presented. Next, the opportunities facing nematology in the next decade are outlined, as well as the resources needed to address these priorities. The safety and sustainability of U.S. food and fiber production depends on public and administrative understanding of the importance of nematodes, the drastic effects of nematodes on many agricultural and horticultural crops, and the current research priorities of nematology.     

Genetic engineering of Oryza sativa by particle bombardment

Genetic engineering of rice (Oryza sativa L. cv. Pusa basmati 1) using synthetic Cry1Ac gene has been achieved by “particle bombardment”. Scutellar tissues excised after 5 – 6 d from mature seeds cultured on induction medium were bombarded using gold particles coated with a mixture of Cry1Ac and marker genes on medium with osmoticum. Bombarded tissues were subjected to 30 mg dm⁻³ hygromycin selection for two cycles. The selected calli after GUS assay were transferred to shoot regeneration medium. Regenerated shoots were rooted and plantlets (T₀) were grown to full maturity. Polymerase chain reaction (PCR) analysis of T₀ plants using Cry1Ac specific primers revealed the presence of Cry1Ac gene in 65 % plants. Phenotypic assay, β-glucuronidase assay and PCR during T₁ generation revealed the inheritance of the Cry1Ac and marker genes along with the native plant genes.     

Plasmid RP4 host-lethal function kilA and its repressor korA sequences are part of the cryptic tellurite resistance transposon Tn521

The normally silent 4.5 kb tellurite resistance transposon Tn521 of RP4 has been shown to carry sequences from both the flanking kilA and korA loci of this broad host range plasmid. The major portion of both of these sequences were used as probes to examine DNA homology in Southern transfer hybridization experiments with plasmid recipients of Tn521 chosen from varying incompatibility groups. In the case of every recipients molecule analyzed using either probe, DNA homology was observed.