Effects of photoperiod and moisture availability on shoot growth, seedling morphology, and cuticle and epicuticular wax features of container-grown western hemlock seedlings

1989 ◽  
Vol 19 (1) ◽  
pp. 122-131 ◽  
Author(s):  
Conor O'Reilly ◽  
J. T. Arnott ◽  
John N. Owens
Keyword(s):  
Shoot Growth ◽  
Moisture Stress ◽  
Epicuticular Wax ◽  
Stress Conditions ◽  
Western Hemlock ◽  
Seedling Morphology ◽  
Growth Cessation ◽  
Moderate Drought ◽  
Morphological Variables ◽  
Collar Diameter

The influence of short-day and long-day photoperiods, and moderate drought stress (−1.0 MPa), all applied for 4 weeks beginning in mid-July, 1986, was studied on greenhouse-grown western hemlock (Tsugaheterophylla (Raf.) Sarg.) seedlings cultured in two Styroblock container cavity sizes. Shoot growth, morphology, and cuticle and epicuticular wax features were investigated. Weekly measurements of shoot growth were made from early June until growth cessation in October. Root collar diameter, shoot length, numbers of branches and needles, and needle lengths were recorded after shoot growth cessation in another subsample of trees. Shoot growth rapidly ceased under short days, whereas free growth continued under long days. Moisture stress had no effect on shoot growth phenology but significantly reduced final values for all morphological variables. The trends were similar in seedlings from both container sizes, but values were greater in those from the larger containers. Long days increased the total number of leaves and branches, especially under no moisture stress conditions. Under long days, stem unit and needle lengths were increased in the proximal portion of the shoot, whereas moisture stress alone reduced these values in the distal section of the shoot. Dormancy induction treatments had little effect on needle cuticle and epicuticular wax features, although fusion of wax rodlets in the stomata was less common under moisture stress conditions.

Effect of nursery culture on morphological development of western hemlock seedlings during field establishment. II. Survival, shoot length components, and needle length

1994 ◽  
Vol 24 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Conor O'Reilly ◽  
J.N. Owens ◽  
J.T. Arnott ◽  
B.G. Dunsworth
Keyword(s):  
Shoot Growth ◽  
Unit Length ◽  
Moisture Stress ◽  
Western Hemlock ◽  
Morphological Development ◽  
Needle Length ◽  
Nursery Culture ◽  
Reverse Pattern ◽  
Dormancy Induction ◽  
Short Days

Western hemlock (Tsugaheterophylla (Raf.) Sarg.) seedlings grown in two different container cavities that received four different dormancy induction treatments, short (SD) or long days (LD) in combination with moisture stress (D) or no stress (W) in the greenhouse, and lifted and placed in cold storage (November, January, or March), were planted on two adjacent coastal reforestation sites in British Columbia and monitored for survival and morphological development. Survival was greatest in seedlings grown in the larger cavities in the greenhouse, in seedlings lifted in March, and in seedlings not treated to moisture stress. Seedling shoots had more stem units on the southeast than the northwest site, but the amount varied with nursery treatment. Seedlings from the LD treatments produced more stem units during free growth and lammas growth than those from the SD treatment. Nevertheless, most shoot growth was predetermined in the buds during nursery culture, accounting for a minimum of 67% of the final number of stem units. Stem unit length (SUL) was longer in seedlings on the southeast site than on the northwest site for those treated to LD in the nursery. Seedlings treated to short days showed the reverse pattern (SDW) to this, or were unaffected by site (SDD). Shoots and needles were shortest for seedlings from the SDD treatment and for those lifted in November. Shoot growth was greatest for seedlings lifted in March and for those treated with LD, mainly owing to their longer SUL. Lammas growth was most frequent in seedlings from the smaller cavities, and in those from the November and March lifts.

scholarly journals Mapping of Quantitative Trait Loci Controlling Adaptive Traits in Coastal Douglas Fir. III. Quantitative Trait Loci-by-Environment Interactions

Genetics ◽  
2003 ◽  
Vol 165 (3) ◽  
pp. 1489-1506
Author(s):  
Kathleen D Jermstad ◽  
Daniel L Bassoni ◽  
Keith S Jech ◽  
Gary A Ritchie ◽  
Nicholas C Wheeler ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Complex Traits ◽  
Moisture Stress ◽  
Interval Mapping ◽  
Douglas Fir ◽  
Adaptive Traits ◽  
Growth Cessation ◽  
Trait Loci ◽  
Growth Initiation

Abstract Quantitative trait loci (QTL) were mapped in the woody perennial Douglas fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco) for complex traits controlling the timing of growth initiation and growth cessation. QTL were estimated under controlled environmental conditions to identify QTL interactions with photoperiod, moisture stress, winter chilling, and spring temperatures. A three-generation mapping population of 460 cloned progeny was used for genetic mapping and phenotypic evaluations. An all-marker interval mapping method was used for scanning the genome for the presence of QTL and single-factor ANOVA was used for estimating QTL-by-environment interactions. A modest number of QTL were detected per trait, with individual QTL explaining up to 9.5% of the phenotypic variation. Two QTL-by-treatment interactions were found for growth initiation, whereas several QTL-by-treatment interactions were detected among growth cessation traits. This is the first report of QTL interactions with specific environmental signals in forest trees and will assist in the identification of candidate genes controlling these important adaptive traits in perennial plants.

Wheat flag leaf epicuticular wax morphology and composition in response to moderate drought stress are revealed by SEM, FTIR-ATR and synchrotron X-ray spectroscopy

2017 ◽  
Vol 162 (3) ◽  
pp. 316-332 ◽  
Author(s):  
Ian R. Willick ◽  
Rachid Lahlali ◽  
Perumal Vijayan ◽  
David Muir ◽  
Chithra Karunakaran ◽  
...  
Keyword(s):  
Drought Stress ◽  
Flag Leaf ◽  
Epicuticular Wax ◽  
X Ray ◽  
Moderate Drought ◽  
Leaf Epicuticular Wax

Evaluation and Genetic Analysis of a Segregating Sorghum Population under Moisture Stress Conditions

2019 ◽  
Vol 23 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Techale Birhan ◽  
Kassahun Bantte ◽  
Andrew Paterson ◽  
Mihrete Getenet ◽  
Aregash Gabizew
Keyword(s):  
Genetic Analysis ◽  
Moisture Stress ◽  
Stress Conditions

Using marker-aided selection to improve tree growth response to abiotic stress

1992 ◽  
Vol 22 (7) ◽  
pp. 1018-1030 ◽  
Author(s):  
C. G. Tauer ◽  
S. W. Hallgren ◽  
B. Martin
Keyword(s):  
Abiotic Stress ◽  
Drought Stress ◽  
Linkage Map ◽  
Loblolly Pine ◽  
Growth Response ◽  
Moisture Stress ◽  
Growth Responses ◽  
Intractable Problems ◽  
Moderate Drought ◽  
Continue Growth

The ability to locate quantitative trait loci (QTL) on a restriction fragment length polymorphism (RFLP) genetic linkage map will provide tree breeders the means to overcome some currently intractable problems inherent to breeding long-lived tree species. These RFLP–QTL maps will allow early, indirect, marker-aided selection (MAS) in breeding programs. This paper explores the opportunities and limitations of MAS, an approach to developing an RFLP–QTL marker map, and use of the map in breeding loblolly pine (Pinustaeda L.) for improved growth response to abiotic stress; specifically, drought stress. Growth responses under moderate drought stress are important to long-term forest productivity, because on most sites loblolly pine is subjected to growth-limiting moisture stress during part of almost every growing season. MAS provides new precision and reliability in identifying and breeding trees that are able to continue growth under moderate stress, and perhaps provides a unique opportunity for improving tree productivity on moderately stressful sites. Traits potentially related to growth under stress are identified, and their suitability for placement and use on an RFLP–QTL linkage map is discussed.

Postdormancy seed-cone development and the pollination mechanism in western hemlock (Tsugaheterophylla)

1989 ◽  
Vol 19 (1) ◽  
pp. 44-53 ◽  
Author(s):  
Anna M. Colangeli ◽  
John N. Owens
Keyword(s):  
Pollen Grains ◽  
Pollen Tubes ◽  
Epicuticular Wax ◽  
Western Hemlock ◽  
Bud Burst ◽  
Pollination Mechanism ◽  
Seed Cone ◽  
Cone Development ◽  
And Function

The development and function of the pollination mechanism is described for hemlock (Tsugaheterophylla (Raf.) Sarg.). Controlled pollinations at various stages following bud burst were used to define the period of maximum receptivity. Western hemlock has a pollination mechanism unlike that observed in other native conifers. The pollen grains were not taken into the micropyles; instead, the roughly sculptured pollen grains adhered to the long epicuticular wax covering the bracts. Seed cones became receptive to pollen soon after the bracts emerged from the bud scales and remained receptive until shortly before cone closure. Several days after the cones fully emerged beyond the bud scales, the ovuliferous scales elongated over the bracts, trapping the pollen between the bracts and scales. Several weeks after pollination, pollen germinated on the bracts and formed long pollen tubes which grew towards and into the micropyles.

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