scholarly journals STUDIES ON HEADING DATE FOR SYNCHRONIZATION AND HYBRIDIZATION OF FIVE RICE VARIETIES UNDER SHORT DAY LENGTH AND NEUTRAL DAY LENGTH.

2018 ◽  
Vol 6 (1) ◽  
pp. 909-916
Author(s):  
ZinWai Maw ◽  
Keyword(s):  
Heading Date ◽  
Day Length ◽  
Rice Varieties ◽  
Short Day

scholarly journals Reversion of the photoperiod dependence of flowering in rice with synthetic Hd1-microProteins

2018 ◽  
Author(s):  
Tenai Eguen ◽  
Jorge Gomez Ariza ◽  
Kaushal Kumar Bhati ◽  
Bin Sun ◽  
Fabio Fornara ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Heading Date ◽  
Day Length ◽  
Dependent Manner ◽  
Yield Analysis ◽  
Rice Plants ◽  
Short Day ◽  
Long Day ◽  
Long Day Plants

SUMMARYRice (Oryza sativa) is a facultative short-day plant that flowers very late when grown in non-inductive long day conditions. Photoperiod-dependent flowering in rice is regulated by heading date (Hd1) which acts as both an activator and repressor of flowering in a day length-dependent manner. In order to regulate flowering of rice in long days (LD), overexpression of a synthetic Hd1miP, which is capable of interacting with Hd1, was employed. Transgenic Hd1miP rice plants flowered significantly earlier when grown in LD compared to SD, showing that synthetic microProteins can be used to revert short-day plants to long-day plants. Yield analysis revealed that although the OX-Hd1miP grains are comparable to WT in terms of the size of the grains produced, OX-Hd1miP plants like hd1 knockout plants, are compromised in the number of grains produced and the grain maturity rate, suggesting an additional unrecognized role of Hd1 in grain maturity.

scholarly journals Yield and grain dimensions of T. Aman rice varieties as influenced by date of transplanting

2016 ◽  
Vol 2 (3) ◽  
pp. 442-450
Author(s):  
Syeda Nuzhat Reza ◽  
Nahid Nadia Tani ◽  
Muhammad Salim ◽  
Ahmed Khairul Hasan ◽  
Mst Arjina Akter
Keyword(s):  
Low Temperature ◽  
Field Experiment ◽  
Grain Yield ◽  
Yield Components ◽  
Day Length ◽  
Rice Varieties ◽  
Short Day ◽  
Yield Parameters ◽  
Two Factors ◽  
Plot Design

A field experiment was carried out at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh, during June 2013 to December 2013 to study the yield and grain dimensions of transplant aman rice varieties as influenced by date of transplanting. The experimental factors comprised of two factors namely, date of transplanting and variety. Date of transplanting comprised of 18 July, 19 August and 18 September. The variety comprised of Binadhan-7, BRRI dhan57, BR11 and Bashiraj. The experimental field was laid out in a split plot design. Most of the yield parameters were significantly affected by the date of transplanting. The yield and yield contributing characters were highest at 19 August transplanting and lowest at 18 September transplanting. Variety had significant effect on most of the yield and yield contributing characters. BR11 gave the highest grain yield (4.47 t ha-1) and the lowest value was obtained in BRRI dhan57. Among the grain dimensions, Binadhan-7 with 18 July transplanting gave the highest grain length (9.64 mm) whereas BR11 with 18 September transplanting gave the lowest value (7.82mm). Results showed that yield components were highest at 19 August transplanting and after that the reduction occurred at 18 September may be due to low temperature and short day length at flowering stage.Asian J. Med. Biol. Res. September 2016, 2(3): 442-450

scholarly journals Meta-QTL and ortho-MQTL analyses identified genomic regions controlling rice yield, yield-related traits and root architecture under water deficit conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bahman Khahani ◽  
Elahe Tavakol ◽  
Vahid Shariati ◽  
Laura Rossini
Keyword(s):  
Water Deficit ◽  
Root Architecture ◽  
Agronomic Traits ◽  
Heading Date ◽  
Dry Weight ◽  
Genetic Dissection ◽  
Rice Varieties ◽  
Average Confidence ◽  
Stable Qtls ◽  
Genomic Regions

AbstractMeta-QTL (MQTL) analysis is a robust approach for genetic dissection of complex quantitative traits. Rice varieties adapted to non-flooded cultivation are highly desirable in breeding programs due to the water deficit global problem. In order to identify stable QTLs for major agronomic traits under water deficit conditions, we performed a comprehensive MQTL analysis on 563 QTLs from 67 rice populations published from 2001 to 2019. Yield and yield-related traits including grain weight, heading date, plant height, tiller number as well as root architecture-related traits including root dry weight, root length, root number, root thickness, the ratio of deep rooting and plant water content under water deficit condition were investigated. A total of 61 stable MQTLs over different genetic backgrounds and environments were identified. The average confidence interval of MQTLs was considerably refined compared to the initial QTLs, resulted in the identification of some well-known functionally characterized genes and several putative novel CGs for investigated traits. Ortho-MQTL mining based on genomic collinearity between rice and maize allowed identification of five ortho-MQTLs between these two cereals. The results can help breeders to improve yield under water deficit conditions.

scholarly journals Managing flowering time in Miscanthus and sugarcane to facilitate intra- and intergeneric crosses

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0240390
Author(s):  
Hongxu Dong ◽  
Lindsay V. Clark ◽  
Xiaoli Jin ◽  
Kossonou Anzoua ◽  
Larisa Bagmet ◽  
...  
Keyword(s):  
Flowering Time ◽  
High Latitude ◽  
Floral Induction ◽  
Day Treatment ◽  
Day Length ◽  
Close Relative ◽  
Short Day ◽  
Culm Length ◽  
Low Latitudes ◽  
Short Days

Miscanthus is a close relative of Saccharum and a potentially valuable genetic resource for improving sugarcane. Differences in flowering time within and between Miscanthus and Saccharum hinders intra- and interspecific hybridizations. A series of greenhouse experiments were conducted over three years to determine how to synchronize flowering time of Saccharum and Miscanthus genotypes. We found that day length was an important factor influencing when Miscanthus and Saccharum flowered. Sugarcane could be induced to flower in a central Illinois greenhouse using supplemental lighting to reduce the rate at which days shortened during the autumn and winter to 1 min d-1, which allowed us to synchronize the flowering of some sugarcane genotypes with Miscanthus genotypes primarily from low latitudes. In a complementary growth chamber experiment, we evaluated 33 Miscanthus genotypes, including 28 M. sinensis, 2 M. floridulus, and 3 M. ×giganteus collected from 20.9° S to 44.9° N for response to three day lengths (10 h, 12.5 h, and 15 h). High latitude-adapted M. sinensis flowered mainly under 15 h days, but unexpectedly, short days resulted in short, stocky plants that did not flower; in some cases, flag leaves developed under short days but heading did not occur. In contrast, for M. sinensis and M. floridulus from low latitudes, shorter day lengths typically resulted in earlier flowering, and for some low latitude genotypes, 15 h days resulted in no flowering. However, the highest ratio of reproductive shoots to total number of culms was typically observed for 12.5 h or 15 h days. Latitude of origin was significantly associated with culm length, and the shorter the days, the stronger the relationship. Nearly all entries achieved maximal culm length under the 15 h treatment, but the nearer to the equator an accession originated, the less of a difference in culm length between the short-day treatments and the 15 h day treatment. Under short days, short culms for high-latitude accessions was achieved by different physiological mechanisms for M. sinensis genetic groups from the mainland in comparison to those from Japan; for mainland accessions, the mechanism was reduced internode length, whereas for Japanese accessions the phyllochron under short days was greater than under long days. Thus, for M. sinensis, short days typically hastened floral induction, consistent with the expectations for a facultative short-day plant. However, for high latitude accessions of M. sinensis, days less than 12.5 h also signaled that plants should prepare for winter by producing many short culms with limited elongation and development; moreover, this response was also epistatic to flowering. Thus, to flower M. sinensis that originates from high latitudes synchronously with sugarcane, the former needs day lengths >12.5 h (perhaps as high as 15 h), whereas that the latter needs day lengths <12.5 h.

scholarly journals Effects of Photoperiodism and Other Factors on the Improvement of Pigeonpea Varieties

1969 ◽  
Vol 48 (3) ◽  
pp. 232-235
Author(s):  
Arturo Riollano
Keyword(s):  
Day Treatment ◽  
Breeding Program ◽  
Flower Induction ◽  
Day Length ◽  
Flower Formation ◽  
Length Of Day ◽  
Short Day ◽  
Late Variety ◽  
Polyethylene Bags

Studies on the effects of photoperiodism and other factors were conducted to obtain information which might be useful in a breeding program with pigeonpeas. The information was sought for accelerating this work in a region where extremes of day-length vary by only 2 hours because of its location in latitude 18°. By shortening the length of day to 8 hours through the use of a darkroom, and planting during the month of February, it was possible to induce flower formation 4 months earlier in two early varieties and 7 weeks earlier in a late variety. However, this short-day treatment did not appreciably affect the time of flower induction in an all-season, or "Totiempo" variety. One-gallon tin-can containers and 10-inch polyethylene bags were found satisfactory for growing pigeonpea plants of different varieties.

scholarly journals Increasing photoperiod stimulates the initiation of spring migratory behaviour and physiology in a facultative migrant, the pine siskin

2018 ◽  
Vol 5 (8) ◽  
pp. 180876 ◽  
Author(s):  
Ashley R. Robart ◽  
Mali M. K. McGuire ◽  
Heather E. Watts
Keyword(s):  
Experimental Test ◽  
Spring Migration ◽  
Fat Deposition ◽  
Day Length ◽  
Environmental Cues ◽  
Migratory Restlessness ◽  
Migratory Behaviour ◽  
Behavioural Changes ◽  
Short Day

The transition to a migratory state involves coordinated changes in physiology and behaviour. In species with regular, predictable (obligate) migrations, increasing day length triggers the expression of a spring migratory state and androgens play an important role in stimulating its development. By contrast, we know little about the environmental cues and endocrine mechanisms that regulate migration in species with less predictable (facultative) migrations. Here, we tested whether photoperiod stimulates a migratory state in a facultative nomadic migrant, the pine siskin ( Spinus pinus ). We exposed wintering birds to either a naturally increasing or short-day photoperiod and measured physiological and behavioural changes indicative of a migratory state. We also examined changes in circulating hormones that may play a role in the migratory transition. Natural-day, but not short-day, birds displayed physiological preparations for migration, including increases in fat deposition, and showed increased levels of migratory restlessness. We found no evidence for a role of corticosterone in the migratory transition, but testosterone may be important. This study is the first experimental test of the role of photoperiod in regulating facultative migration and demonstrates that the predictive cue used by many obligate migrants to time spring migration is also important in a facultative migrant.

scholarly journals Day-Length Control of Inflorescence Initiation in the Grass Rottboellia Exaltata L.F.

1962 ◽  
Vol 15 (2) ◽  
pp. 291 ◽  
Author(s):  
LT Evans
Keyword(s):  
Day Length ◽  
Inflorescence Development ◽  
Short Day ◽  
Critical Photoperiod ◽  
The One ◽  
Short Days

R. exaltata is a strict short�day plant with a critical photoperiod of about 13 hr. The number of short days required for inflorescence initiation varies with age, being 6 with plants 5 weeks old. Exposure to additional short days increases the rate of inflorescence development. The expanding leaf is the one most sensitive to short.day induction and removal of the leaves below it accelerates inflorescence development.

The effect of failure in extended and intermittent photoperiodic lighting on the growth of white spruce container seedlings

1985 ◽  
Vol 15 (4) ◽  
pp. 734-737 ◽  
Author(s):  
J. T. Arnott ◽  
C. S. Simmons
Keyword(s):  
Dark Period ◽  
Dry Weight ◽  
White Spruce ◽  
Shoot Length ◽  
Day Length ◽  
Lighting System ◽  
Usual Definition ◽  
Short Day ◽  
Lighting Systems ◽  
Definition Of

White spruce seedlings (seed source, 58°50′ N) were grown in a container nursery at Victoria, B.C. (48°28′ N) under the following two photoperiod regimes: (i) natural day length artifically extended to 18 h (120 lx from an incandescent source); (ii) natural day length with dark period interruption for 2.5 min every 30 min (120 lx from an incandescent source). Beginning on July 17, 12 weeks after sowing, batches of seedlings experienced a simulated failure of the lighting systems of from 0 to 9 nights. Although the reduced photoperiod did not fit the usual definition of a short day, failure of the lighting system in (i) and (ii) caused significant reductions in seedling shoot length and dry weight and a significant increase in root dry weight.

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