The photoperiodic sensitivity of some spring wheats with special reference to the variety thatcher

1966 ◽  
Vol 17 (5) ◽  
pp. 591 ◽  
Author(s):  
AT Pugsley
Keyword(s):  
Genetic Analysis ◽  
Special Reference ◽  
American Variety ◽  
Ear Development ◽  
Photoperiodic Sensitivity ◽  
Minor Gene ◽  
Floral Primordia ◽  
Short Days

Earlier studies of the processes leading to flowering in spring wheats have been extended to embrace a genetic analysis of photoperiodic sensitivity in several spring varieties. The American variety Thatcher proved particularly sensitive to the short days experienced in the greenhouse during the winter months. Compared with Selkirk, Thatcher is later under short days, and this lateness appears to be conditioned by a second minor gene over and above that already recognized in Selkirk. The backcrossing procedure has been used to establish two new recombinant genotypes intermediate in behaviour between the parental varieties Triple Dirk and Thatcher. Abnormalities in ear development of sensitive varieties like Thatcher were consistently produced when plants raised under short days were transferred to long days soon after the estimated time of initiation of floral primordia.

scholarly journals Chrysanthemum Cultivars Differ in Response to Photoperiod when Grown under Far-red Absorbing Filters

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 437A-437
Author(s):  
M.J. McMahon
Keyword(s):  
Acetic Acid ◽  
Ethyl Alcohol ◽  
The Other ◽  
Short Day ◽  
Long Day ◽  
Floral Primordia ◽  
Lateral Branches ◽  
And Control ◽  
Short Days

Two chrysanthemum [Dendranthema × grandiflorum (Ramat) Kitamura] cultivars, Bright Golden Anne and Spears, were grown in unfiltered sunlight (control) or under filters that removed far-red (FR) light under long- or short-day photoperiods for a total of four treatments. Eight plants from each cultivar were exposed to each treatment. Tips of lateral branches were harvested every 3 days and preserved in formalin, acetic acid, 70% ethyl alcohol (5:5:90 by volume), then observed and photographed under a dissecting microscope. In `Spears', all short-day treatments developed floral primoridia at the same time and rate and the development was normal. Under long days and under FR-absorbing filters, floral primordia initiated and developed normally, but was delayed several days compared to short days. Plants under long days and control filters also developed normal primoridia, but at a slower rate than any of the other treatments. In `Bright Golden Anne', only short-day treatments developed normal floral primordia. Development was the same regardless of filter. Under long days, plants under FR-absorbing filters eventually initiated floral primordia, but development was abnormal. No floral primordia developed under long-day and control filter conditions. In all cases, `Spears' primoridia development was much more rapid than `Bright Golden Anne'.

scholarly journals Genetic analysis of CTX prophages with special reference toctxBand  rstR alleles ofVibrio choleraeO139 strains isolated from Kolkata over a decade

2010 ◽  
Vol 303 (2) ◽  
pp. 107-115 ◽  
Author(s):  
Amit Raychoudhuri ◽  
Piyali Mukherjee ◽  
Thandavarayan Ramamurthy ◽  
Ranjan K. Nandy ◽  
Yoshifumi Takeda ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
Special Reference

Differences in flowering responses of wheat to temperature and photoperiod

1992 ◽  
Vol 43 (3) ◽  
pp. 575 ◽  
Author(s):  
T Manupeerapan ◽  
JL Davidson ◽  
CJ Pearson ◽  
KR Christian
Keyword(s):  
Growth Rates ◽  
Normal Development ◽  
Vegetative Period ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Ear Development ◽  
Spring Variety ◽  
Before And After ◽  
Accelerated Growth ◽  
Short Days

Apex and ear development were studied in one spring wheat (Hartog) and five winter wheats (Rosella, Maris Templar, Maris Huntsman, Priboy and Krasnodar 39) subjected to vernalizing or non-vernalizing temperatures under either short or long photoperiods until ear initiation (double ridges), followed by either short or long photoperiods until ear emergence. Hartog produced ears in all treatments, and it initiated ears faster than winter varieties in all treatments. Four types of winter wheat were distinguished by their mandatory requirements for ear development. The only winter variety to reach ear emergence without vernalization was Maris Templar; short days were an effective substitute provided that long days were experienced after ear initiation. In Priboy, photoperiod was unimportant both before and after ear initiation. Maris Huntsman and Rosella required long photoperiods after initiation, whereas Krasnodar 39 required long days during vernalization. If these conditions were not met, either the shoot apexes died without producing a terminal spikelet or the ears died before emerging. Plants in all treatments which reached ear emergence proceeded normally to maturity. The suitability of the different types for particular regions is discussed. All varieties in all treatments initiated ears when the shoot apex reached a volume of about 0.13 mm3. Relative growth rates of the apex, related to thermal time, were constant during the vegetative phase; they determined the time to ear initiation and, through it, controlled the time of ear emergence. Differences between varieties in their basic vegetative period are attributed to differences in the relative growth rates of their vegetative apexes. These growth rates were much lower in winter wheats than in the spring variety, but increased sharply in them at or just before the first visible signs of initiation in those treatments which allowed normal development. Vernalization was not the cause of this accelerated growth. In winter wheats, vernalization promoted faster initiation of ears, and hence flowering, and the survival and normal development of initiated ears. It is suggested that vernalization acts by reducing the effectiveness of an inhibitor of cell division.

scholarly journals Effect of a switch in photoperiod on the reproductive development of temperate hybrids of maize.

1982 ◽  
Vol 30 (2) ◽  
pp. 69-83
Author(s):  
P.C. Struik
Keyword(s):  
Indirect Effects ◽  
Time Lag ◽  
Reproductive Development ◽  
Light Phase ◽  
Ear Development ◽  
Long Day ◽  
Number Of Leaves ◽  
Phytotron Experiments ◽  
Short Time ◽  
Short Days

The reaction of maize to a switch in light phase was investigated in 3 phytotron experiments. Number of leaves was increased by a long-day phase (20 h) before tassel initiation but was not affected thereafter. Reproductive development was delayed by long days before tassel initiation and slowed down by long days after tassel initiation but ear development was affected more than tassel development. The time lag between anthesis and silking increased when short days (12 h) were followed by long days and the opposite was true when long days were followed by short days. Direct responses to photoperiod such as number of leaves and tassel branches occurred over a rather short time. Indirect effects such as area of leaves, ht. of plant and length of the ear shoot were max. when daylength no longer affected the number of leaves. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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