scholarly journals Genetic inheritance of photoperiod sensitivity in Runner bean (Phaseolus coccineous L.)

2019 ◽  
pp. 1511-1519
Author(s):  
Mable. M. Mulanya ◽  
Paul. M. Kimani ◽  
Rama D. Narla ◽  
Pascal Okwiri Ojwang
Keyword(s):  
Female Parent ◽  
Photoperiod Sensitivity ◽  
Day Length ◽  
Dominance Model ◽  
Gene Effects ◽  
Short Day ◽  
Long Day ◽  
Runner Bean ◽  
Additive Gene ◽  
Bulk Breeding

Lack of information on the mode of inheritance of photoperiod sensitivity is a constraint to genetic improvement of tropically adapted vegetable runner bean. This study was conducted to determine the inheritance of short-day photoperiod in runner beans. Seven single crosses between female parent; White Emergo (long day imported variety) and seven short day local landraces (Kin 1, Kin 2, Kin 3, Nyeri, Dwarf1, Dwarf 2 and Dwarf 3) were developed in Kenya. The parents, F1, F2 and backcrosses were evaluated at Kabete (warm conditions) and Ol Joro-Orok (cool condtions) under the natural short-day length of 12hrs. From the results, short day parents flowered earlier (within 40-48 days) and formed more racemes (on average 10 racemes/plant) and pods (at least 25pods/plant) than long day parent (White Emergo) at both locations. The populations in the seven cross combinations flowered earlier at the warmer location (Kabete) than cooler one (Ol Joro Orok). In all crosses, F1 and F2 means of days to flowering and number of racemes were within parental range while the backcrosses’ showed means that were close to their recurrent parents. The additive-dominance model [m+a+d] was found to adequately explain the genetic influence on studied traits with additive gene effects accounting for about 90% of the genetic action. The predominance of additive gene action indicates that improvement of this crop for short day adaptation can be easily achieved by trait integration through hybridization followed by pure selection methods such as single seed descent, bulk breeding or pedigree.

A method for induction and quantification of diapause entry in the swede midge (Diptera: Cecidomyiidae)

2012 ◽  
Vol 144 (6) ◽  
pp. 792-800 ◽  
Author(s):  
Lauren E. Des Marteaux ◽  
Marc B. Habash ◽  
Jonathan M. Schmidt ◽  
Rebecca H. Hallett
Keyword(s):  
Diapause Induction ◽  
Day Length ◽  
Retrieval Method ◽  
Short Day ◽  
Long Day ◽  
Rearing Conditions ◽  
Swede Midge ◽  
Pupal Mortality ◽  
Contarinia Nasturtii ◽  
Cool Conditions

AbstractInduction of diapause under laboratory conditions is a valuable tool for the study of dormancy in economic pests such as the swede midge, Contarinia nasturtii Kieffer (Diptera: Cecidomyiidae). In the present study, diapause in larval swede midge was achieved via manipulation of rearing photoperiod and temperature. Frequency of diapause was assessed by sieve separation of diapause cocoons from pre-sifted peat substrate following emergence of pupating individuals. Mean diapause frequency for swede midge larvae reared under cool conditions with short day length or cool conditions with decreasing day lengths were 45.2% and 19.5%, respectively. Only 1.2% of swede midge reared under warm, long day length conditions entered diapause. A small percentage of larvae neither pupated nor entered diapause and remained in substrate long after other individuals had emerged as adults. This behaviour was more prevalent under cool and short or decreasing day length rearing conditions. Approximately 76% of the larvae used for diapause induction were recovered with the present larval and cocoon retrieval method, and premature (larval and pupal) mortality averaged 18.2%. Although diapause occurred in the present study, conditions resulting in higher diapause frequencies should be investigated and attempts should be made to improve survival and recovery of individuals.

scholarly journals Responses of earliness and lateness genes for heading to different photoperiods, and specific response of a gene or a pair of genes to short day length in rice

Hereditas ◽  
2019 ◽  
Vol 156 (1) ◽  
Author(s):  
Birendra Bahadur Rana ◽  
Misa Kamimukai ◽  
Mukunda Bhattarai ◽  
Yohei Koide ◽  
Masayuki Murai
Keyword(s):  
Genetic Factors ◽  
Day Length ◽  
Specific Response ◽  
Near Isogenic Lines ◽  
Heading Time ◽  
Short Day ◽  
Long Day ◽  
Days To Heading ◽  
Important Trait ◽  
Spring Sowing

Abstract Background Heading time is an important trait for regional and seasonal adaptabilities in rice, and is controlled by genetic factors in relation with environmental factors, mainly day length and temperature. The following genes controlling heading were examined for their responses to six different environmental conditions involving different day lengths using five early near-isogenic lines (NILs) of T65-R and three late NILs of T65wx: two earliness genes, Ef1 and Efx controlling basic vegetative phase (BVG), and m-Ef1, the enhancer to the former gene; and two lateness genes, Se1-pat(t) and se-pat controlling photo-sensitivity and BVG, respectively. T65-R and T65-T were different accessions of Taichung 65. T65wx is a NIL of T65-T carrying wx. Results The five early NILs of T65-R were in the order of ER50 (Ef1, Efx, m-Ef1) < ER40 (Ef1, m-Ef1) ≤ ER20 (Ef1, Efx) < ER1 (Ef1) ≤ ER21 (Efx) < T65-R regarding days to heading (DTH) under two spring-sowing and one summer-sowing paddy field (PF) conditions. The three late NILs of T65wx were in the order of LF3 (Se1-pat(t)) ≤ LF2 (Se1-pat(t), se-pat) ≤ T65wx < LF1 (se-pat) under two short-day conditions (10-h photoperiod condition with artificial-light and natural short-day condition from autumn to winter). The NILs and T65wx were in the order of T65wx < LF3 < LF1 < LF2 under the two spring-sowing PF (long day) conditions. T65-R (Ac-ef1) was 2.8 or 5.1 days earlier in DTH than T65-T (ac-ef1) under the two spring-sowing PF conditions. However, T65-R was 19 and 10 days earlier than T65-T under the two short-day conditions. Conclusions Earliness gene(s) and their combinations reduced DTH regardless of photoperiod lengths. Se1-pat(t) increased DTH under long-day conditions but decreased it under short-day conditions, while se-pat elongated DTH under both short-day and long-day conditions indicating that se-pat is responsible for BVG. The se-pat increased DTH by adding its effect over that of Se1-pat(t) under long-day conditions. However, this increasing effect of DTH by se-pat was almost completely masked when it coexisted with Se1-pat(t) under the short-day conditions. Notably, the response of Ac-ef1 to day length was found to delay heading under the short-day conditions.

scholarly journals Hybridizing ability and heterosis between Eucalyptus urophylla and E. tereticornis for growth and wood density over two environments

2014 ◽  
Vol 63 (1-6) ◽  
pp. 15-23 ◽  
Author(s):  
Q. Weng ◽  
X. He ◽  
F. Li ◽  
M. Li ◽  
X. Yu ◽  
...  
Keyword(s):  
Wood Density ◽  
Genetic Correlations ◽  
Female Parent ◽  
Hybrid Breeding ◽  
Eucalyptus Urophylla ◽  
Narrow Sense Heritability ◽  
Gene Effects ◽  
Additive Gene ◽  
Factorial Mating ◽  
Hybrid Growth

Abstract Interspecific hybrids of Eucalyptus urophylla × E. tereticornis in a factorial-mating design were used to analyze general hybridizing ability (GHA), specific hybridizing ability (SHA) and heterosis for height (H; 0.5, 1.5, 2.5, 4 and 7.5 years in age), diameter at breast height (D; ages 1.5, 2.5, 4 and 7.5) and wood density (WD; age 7.5) across two environments. The GHA variances were significant for all traits, and those of the SHA were also significant for most of the traits but with less magnitude, indicating the greater importance of additive gene effects in explaining the phenotypic variation among hybrids. The narrow-sense heritability (h2) and dominance (d2) estimates with hybrid growth and wood density ranged between 0.02±0.05 (d2 in D7.5) and 0.23±0.10 (d2 in H1.5) over the different ages, suggesting weak additive and dominant effects on these traits. Additive genetic correlations of growth with wood density were weak at age 7.5. Female general combining ability (GCA) based on maternal open-pollinated families was not necessarily a good indicator of GHA as their correlations were 0.48 (P=0.17), 0.65 (P=0.04) and -0.56 (P=0.10) for H7.5, D7.5 and WD7.5, respectively. A great proportion of hybrids showed positive female-parent heterosis (FPH) at age 7.5, with the highest relative FPH of 47.2% in D7.5. This study demonstrates the heterosis between inter-sectional species and could have implications for E. urophylla × E. tereticornis hybrid breeding.

scholarly journals Four Hour Temporal Relation of 5-HTP and L-DOPA Induces Inhibitory Responses in Recrudescing Gonad of Indian Palm Squirrel (Funambulus pennantii)

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Ranjana Jaiwal ◽  
C. M. Chaturvedi
Keyword(s):  
Environmental Factors ◽  
Basic Mechanism ◽  
Inhibitory Effect ◽  
Temporal Relation ◽  
Day Length ◽  
Short Day ◽  
Long Day ◽  
Testicular Recrudescence ◽  
Neurotransmitter Activity ◽  
Seasonally Breeding

Daily injections of L-dihydroxyphenylalanine (L-DOPA, dopamine precursor) given 4 h after 5-hydroxytryptophan (5-HTP, serotonin precursor) induced inhibitory responses in recrudescing gonad (in the first week of December) of Indian palm squirrel, a seasonally breeding subtropical animal. Other temporal relations (L-DOPA given at 0, 8, 12, 16, and 20 h after 5-HTP administration) did not show any effect on the recrudescing gonad. This inhibitory effect of 4 h was evident under short day length (6 : 18) group but was masked by the increasing day length of nature (NDL, late December onwards) and increased photoperiod of long day group (16 : 8). It is apparent that seasonal testicular recrudescence of Indian palm squirrel during short day length by 4 h relation of 5-HTP and L-DOPA is not a pharmacological effect but actually is an alteration of seasonality in this annually breeding mammal. It seems that endogenous mechanism controlling seasonal testicular recrudescence of Indian palm squirrel is reset by timed daily injections of these neurotransmitter drugs. It is suggested that in spite of different environmental factors (photoperiod, humidity, etc.) used by different species to time their annual reproduction, basic mechanism of seasonality appears to be the same, that is, the temporal synergism of neurotransmitter activity.

Effects of shortened day length upon translocation and starch accumulation by maize, wheat, and pangola grass leaves

1982 ◽  
Vol 60 (8) ◽  
pp. 1304-1309 ◽  
Author(s):  
Richard C. Sicher ◽  
William G. Harris ◽  
Diane F. Kremer ◽  
N. Jerry Chatterton
Keyword(s):  
Carbon Assimilation ◽  
Pool Size ◽  
Day Length ◽  
Starch Accumulation ◽  
Leaf Extracts ◽  
Sucrose Transport ◽  
Chase Period ◽  
Short Day ◽  
Long Day ◽  
Total Pool

Rates of leaf starch accumulation in maize, wheat, and pangola grass were approximately doubled when plants were shifted from long to short day lengths, 4 days prior to measurement. There were only small changes in carbon assimilation rates and specific leaf weights. After a brief exposure to 14CO2 and after a 2-h-chase period, total label was higher in leaves of long to short day length than in long day length plants. Most of the increased 14C radioactivity in leaf extracts of long to short day length plants was recovered in the starch, protein, and neutral fractions. The translocation of 14C-labeled assimilates to roots was less in long to short day length then in long day length plants. Sucrose was increased in leaves and decreased in roots following a shift from long to short day lengths. The above findings indicated that the accumulation of assimilates in leaves of long to short day length plants was due in part to a lowered rate of sucrose transport. The rate of sucrose movement was not directly proportional to its total pool size in source leaves.

INFLUENCE OF BREED, BIRTH DATE, AGE AND BODY WEIGHT ON TESTICULAR MEASUREMENTS OF GROWING RAMS MAINTAINED IN A CONTROLLED ENVIRONMENT

1983 ◽  
Vol 63 (4) ◽  
pp. 835-847 ◽  
Author(s):  
J. N. B. SHRESTHA ◽  
P. S. FISER ◽  
G. A. LANGFORD ◽  
D. P. HEANEY
Keyword(s):  
Body Weight ◽  
Continuous Light ◽  
Skinfold Thickness ◽  
Day Length ◽  
Birth Date ◽  
Short Day ◽  
Scrotal Circumference ◽  
Long Day ◽  
Expanded Metal ◽  
Time Of Breeding

Testicular measurements, including scrotal circumference (SC), testis length (TL), testis width (TW), scrotal skinfold thickness (ST) and tonometer score (TS), and body weight (BW) were collected from 233 rams of three synthetic strains, Suffolk and Finnish Landrace breeds, at 6, 8 and 10 mo of age, at the time of first breeding in September 1981 (11–13 mo) and second breeding in April 1982 (18–21 mo). Rams were exposed to continuous light from birth to weaning (21 ± 3 days of age), to a long day-length (16 h light: 8 h darkness) from weaning to 6 mo and then to a short day-length (9 h light: 15 h darkness) to the time of breeding. Subsequently, the rams were exposed to 4 mo of long day-length followed by a 4 mo of short day-length. All rams were hysterectomy derived, housed indoors year-round on expanded metal floors in windowless barns and reared artificially. Breed, birth date, age of ram and body weight were found to have important effects (P < 0.05) on testicular measurements of growing rams, whereas, age of dam and litter size effects were absent (P > 0.05). In general, meat-type sire breeds (Strain 1 and Suffolk) had larger SC, TL, TW and BW when compared to the fecund sheep breeds (Finnish Landrace, Strains 2 and 3). Testicular measurements and BW of Finnsheep rams were smaller when compared to all other rams examined. The significance of breed and birth date effects varied as the ram progressed in age. Testicular measurements and BW increased with age of ram from 6 to 8 mo but TS showed no change. SC and BW increased substantially at 18–21 mo (April) compared to 11–13 mo (September), whereas TL, TW, ST and TS declined. SC, TL and TW were significantly correlated with each other at all ages. ST and TS were independent traits with no significant relationship to SC, TL, TW and BW. Key words: Sheep, testicular measurements, breed, birth date, age of ram, body weight

Latitude affects photoperiod-induced changes in immune response in meadow voles (Microtus pennsylvanicus)

2005 ◽  
Vol 83 (10) ◽  
pp. 1271-1278 ◽  
Author(s):  
L M Pyter ◽  
Z M Weil ◽  
R J Nelson
Keyword(s):  
Immune Responses ◽  
Microtus Pennsylvanicus ◽  
Day Length ◽  
Delayed Type Hypersensitivity ◽  
Deer Mice ◽  
Meadow Voles ◽  
Short Day ◽  
Long Day ◽  
Induced Changes ◽  
Short Days

Animals use day length (photoperiod) to time seasonal adaptations to annual changes in their environment. Reproductive adjustments in deer mice (Peromyscus maniculatus (Wagner, 1845)) from high latitudes are more extensive in response to short days than in deer mice from low latitudes. These adjustments may permit individuals to survive the severe seasonal changes (e.g., temperature and food abundance) in high-latitude environments. Immune function is also affected by photoperiod. Short days were predicted to result in elevated immune and reproductive responses in meadow voles (Microtus pennsylvanicus (Ord, 1815)) from the Northwest Territories (NWT), Canada (~62°N), compared with voles from Ohio (OH), USA (~39°N). Male voles from both latitudes were maintained in long or short days for 10 weeks prior to a delayed-type hypersensitivity (DTH) immune challenge. Both populations displayed similar testicular regression and reduction of testosterone concentrations in short days. DTH immune responses, however, diverged between the two populations. DTH immune responses were enhanced in long-day NWT voles and short-day OH voles, but decreased in short-day NWT voles and long-day OH voles. Total and free corticosterone concentrations did not explain the latitudinal differences in immune responses. These results suggest that photoperiod affects reproductive and immune systems differently and that immune responses may reflect other environmental factors.

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.

Exogenous T3 mimics long day lengths in Siberian hamsters

2007 ◽  
Vol 292 (6) ◽  
pp. R2368-R2372 ◽  
Author(s):  
David A. Freeman ◽  
Brett J. W. Teubner ◽  
Carlesia D. Smith ◽  
Brian J. Prendergast
Keyword(s):  
Gonadal Development ◽  
Day Length ◽  
Intermediate Step ◽  
Iodothyronine Deiodinase ◽  
Short Day ◽  
Siberian Hamsters ◽  
Long Day ◽  
Long Duration ◽  
Reproductive Response

Siberian hamsters ( Phodopus sungorus) exhibit seasonal cycles of reproduction driven by changes in day length. Day length is encoded endogenously by the duration of nocturnal melatonin (Mel) secretion from the pineal gland. Short-duration Mel signals stimulate reproduction and long-duration signals inhibit reproduction. The mechanism by which Mel signals are decoded at the level of neural target tissues remains uncharacterized. In Siberian hamsters, exposure to short day lengths or injections of Mel in long days results in a decrease in hypothalamic expression of type 2 iodothyronine deiodinase (Dio2) mRNA. Dio2 catalyzes the conversion of the thyroid hormone thyroxine to triiodothyronine (T3). Thus exposure to short and long day lengths should decrease and increase hypothalamic T3 concentrations, respectively. We tested the hypothesis that exogenous T3 administered to short-day hamsters would mimic exposure to long day lengths with respect to gonadal stimulation. Hamsters gestated and raised in short day lengths that exhibited photoinhibition of the testes were given daily subutaneous injections of T3 or saline vehicle for 4 wk beginning at week 12 of life. The results indicate that exogenous T3 induced gonadal growth in short-day hamsters and delayed spontaneous gonadal development by an interval equal to the number of weeks during which T3 was administered. T3 injections delayed gonadal regression if given coincident with the transfer of hamsters from long to short day lengths. These results suggest that T3 mimics long day exposure in Siberian hamsters and may serve as an intermediate step between the Mel rhythm and the reproductive response.

Sign in / Sign up

Export Citation Format

Share Document