Mitotic Index and Cell Cycle of Lemna perpusilla under Different Photoperiods

Mitotic Index and Cell Cycle of Lemna perpusilla under Different Photoperiods.

Nitrate and the Course of Lemna perpusilla Carbon Dioxide Output under Daily Photoperiodic Cycles.

The carbon dioxide output of Lemna perpusilla 6746 on modified Hutner's media under light (dark) cycles of 8 (16) hours is entrained in either of two forms depending on the level of nitrate. With nitrate low or absent, the peak occurs shortly after the start of each dark period, and the minimum, shortly after the start of each light period. With high (about 10 mm) nitrate, an additional or sole...

The mitotic cycle and cell population control.

There is a danger, in the study of the mechanisms of control of mitosis, of oversimplifying the problems. This is particularly so in attempts to extract controlling substances from tissues where the procedures used may take no account of the structural heterogeneity of the system. It has to be recognized that in many tissues one will be dealing with a number of subpopulations, related to each o...

Influence of Short Term Inhibitor Treatment on the Flowering of Lemna perpusilla 6746.

Short term inhibitor treatment can be used to examine the processes that occur during an inductive dark period in the short day plant Lemna perpusilla Torr., strain 6746. Several inhibitors of protein biosynthesis are most effective in reducing per cent flowering when treatment occurs over the 2-hour intervals beginning at the 12th hour or the 14th hour of a 8 (16) photoperiodic cycle. The anti...

Factors Affecting the Water-sensitive Phase of Flowering in the Short Day Plant Lemna perpusilla.

The flowering of Lemna perpusilla strain 6746 is inhibited by daily transfers to water for short periods during a sensitive phase. Supplementing the water with Ca(NO(3))(2) partially reverses the inhibition of flowering while MgSO(4) increases the inhibition. The inhibition by MgSO(4) is overcome by low concentrations of Ca(NO(3))(2). Flower-promoting activity was detected in water and in MgSO(...