Genetic Variation in Frost Tolerance, Uromycladium acaciae Rust Resistance, and Growth in an Acacia mearnsii Population

2021 ◽  
Author(s):  
Julian Moreno Chan ◽  
Fikret Isik

Abstract Genetic variation in frost tolerance, resistance to the rust fungus Uromycladium acaciae, growth, stem form, and gummosis were evaluated in 110 open-pollinated families of black wattle (Acacia mearnsii De Wild). Families were tested at six frost-prone sites in northern KwaZulu-Natal and southeastern Mpumalanga, South Africa. Frost-hardy provenances were susceptible to rust disease and had poor growth. Locally grown F1 seed sources that originated from cold-hardy Australian seed sources had better growth and were tolerant to rust, but at a cost of lower frost tolerance. Considerable genetic variation was observed between families within seed sources for frost damage (hfm2 = 0.77), rust incidence (hfm2 = 0.89), and height (hfm2 = 0.80). The corresponding narrow-sense heritabilities (hi2) were 0.30, 0.80, and 0.32. Genotype-by-environment interaction levels were low for most traits. Except for a strong genetic correlation between tree height and diameter (0.90), all the pairs of traits had weak to moderate genetic correlations. Recurrent selection will be successful in improving frost tolerance and rust incidence. However, the current population comprises limited germplasm that is both tolerant to frost and resistant to rust. Thus, we recommend infusing germplasm from known cold-hardy Australian provenances into the current population to increase genetic variation for frost tolerance, rust, and growth. Study Implications Black wattle (Acacia mearnsii De Wild) is widely planted in South Africa for bark extract and woodchip exports. The species is prone to frost damage and susceptible to rust fungus Uromycladium acaciae, two major limitations to its cultivation. In this study, 110 open-pollinated families of black wattle originated from its native range in Australia and local South African seed sources were studied for frost and disease tolerance. The results from this study suggest that there is considerable variation within species for frost tolerance and fungal disease. We suggest a tandem selection strategy for black wattle farming in South Africa to increase resistance to frost damage and fungal diseases.

1992 ◽  
Vol 82 (2) ◽  
pp. 197-202 ◽  
Author(s):  
D. Donnelly ◽  
F.J. Calitz ◽  
I.M.R. Van Aarde

AbstractA seed-feeding weevil, Melanterius servulus Pascoe, is considered suitable for release against the weed Paraserianthes lophantha. However, host specificity tests have indicated that M. servulus may also develop on the seeds of Acacia mearnsii (black wattle), which is both a weed and a crop plant in South Africa. Seed orchards, which supply the black wattle industry, may therefore need to be protected. The aim of this study was to determine whether the two pyrethroid insecticides presently used in wattle plantations against the wattle bagworm (Kotochalia junodi Heylaerts (Lepidoptera: Psychidae)) are effective against M. servulus. Since M. servulus has not yet been released in South Africa, field trials were not possible, and evidence that black wattle seed orchards can be protected from M. servulus was obtained indirectly, in two stages. Firstly, field trials showed that the two insecticides effectively protect the weed Acacia longifolia from a closely related weevil, Melanterius ventralis Lea, which has already been established as a biocontrol agent. Secondly, quarantine laboratory trials demonstrated that M. ventralis and M. servulus showed similar avoidance responses and similar levels of mortality when exposed to the insecticides. All the evidence indicates that the chemical protection of A. mearnsii seed orchards from M. servulus is possible.


2008 ◽  
Vol 57 (1-6) ◽  
pp. 165-170 ◽  
Author(s):  
C. Sáenz-Romero ◽  
B. L. Tapia-Olivares

AbstractWe explored the patterning of genetic variation among Pinus devoniana Lindl. (also known as P. michoacana Martínez) populations to develop guidelines for seed and seedling movements, intended for improving the matching between genotypes and environments regarding frost tolerance, in reforestation programs. Open-pollinated seed from 16 populations along an altitudinal transect (1600 to 2450 m) were collected near Morelia, State of Michoacán, México. A common-garden provenance test, established with 2.5-year-old seedlings, was assessed for frost resistance conducting a laboratory frost damage test (-9°C). Results indicate that there were significant differences among provenances (P = 0.0261) for frost damage. Variation among provenances was structured as an altitudinal cline, with populations from lower altitudes being the least tolerant to frost. Linear regression statistics suggest that for each increment of 100 m of provenance altitude, there will be a 5.2% decrease in frost damage. We suggest the use of two provisional altitudinal seed zones of 400 m breadth each (lower and upper limits for zone 1: 1600 m and 2000 m of altitude; for zone 2: 2000 and 2400 m, respectively), and for reforestation of a given site, the use of seedlings originated from seed of the same seed zone or within ±200 m of altitude from the elevation of the reforestation site.


HortScience ◽  
2006 ◽  
Vol 41 (7) ◽  
pp. 1531-1536 ◽  
Author(s):  
Jennifer L. Emerson ◽  
John Frampton ◽  
Steven E. McKeand

A series of open-pollinated progeny tests of Fraser fir [Abies fraseri (Pursh) Poir.] was analyzed to determine genetic variation of spring frost damage to the terminal leader and lateral branches after a late season frost in May of the third year in the field. The level of spring frost damage was also compared with bud flush dates that had been measured in the nursery before field planting. Seed sources differed significantly for lateral branch frost damage, and families within source differed significantly for both terminal leader and lateral branch frost damage. Greater terminal and lateral frost damage were significantly associated with greater height for all years. As expected, parent elevation was negatively associated with progeny height. Less lateral frost damage was also associated with later terminal and lateral bud flush dates in the nursery. In addition, higher parent elevation was associated with later lateral bud flush dates of progeny in the nursery. Terminal and lateral bud flush dates in the nursery showed high individual tree within-population heritability values of 0.85 and 0.73, respectively. Similar heritability values for the frost damage measurements were low, 0.045 for terminal leader damage and 0.14 for lateral branch damage. Many of the fast-growing families quickly made up for any loss of height from frost damage so that frost damage should not greatly affect the rotation length.


2006 ◽  
Vol 25 (4) ◽  
pp. 226-247
Author(s):  
F.H. Smith

Daar is reeds baie geskryf oor uitheemse indringerplante, veral Acacia mearnsii De Wild, die swartwattelboom en die skade wat hierdie plante aan die plaaslike ekologie aanrig. In hierdie artikel word aandag gegee aan die ontstaan van die probleem, asook aan die inbring en verspreiding van swartwattelbome in die Republiek van Suid-Afrika (Suid-Afrika). Die probleme wat deur die onbeheerde verspreiding van wattelbome veroorsaak is, het die regering verplig om op te tree ten einde hierdie probleme te bekamp. Voor 1936 was daar aanvanklik geen formele beleid met betrekking tot die invoer, kweek en beheer van hierdie bome nie. Dit het daartoe gelei dat die regering in die wattelbedryf ingegryp het om ’n sekere mate van beheer te vestig en om probleme met betrekking tot uitheemse indringerplante in die algemeen – en die swartwattelboom in die besonder – die hoof te bied. Voorts sal daar ook gelet word op die rol van swartwattel in volhoubare ontwikkeling deur te fokus op die omgewings-/ekologiese probleem van impak op die biodiversiteit en die waterbronne en ook op die voordele wat dit het om woudherstel aan te help. Die artikel bespreek sosiale voordele wat die boom het vir inwoners van landelike gebiede as voorsiener in bou- en konstruksiemateriaal en vuurmaakhout, wat andersins uit die boomveld en/of inheemse woude verkry moet word. Die boom voorsien ook in die houtbehoeftes van die industrie in die vorm van byvoorbeeld pale, pulp en ekstrak. Laastens volg ’n bespreking van die Werk-vir-Water-program. AbatractBlack wattle trees: blessing or curse to South Africa Much has been written about alien invasive plants, especially Acacia mearnsii De Wild, the black wattle tree and the damage done by these plants to the local ecology. In this article cognisance is taken of how the problem was created, the introduction into and the distribution of black wattle trees in the Republic of South Africa (South Africa). Problems experienced by the uncontrolled spreading of wattle trees forced the government to act, as there was no formal policy before 1936 on the importation, cultivation and control thereof. This led to intervention by government in the wattle industry to establish some form of control and to address the problems related to alien invasive plants in general, and the black wattle tree in particular. Furthermore, cognisance will be taken of the role the black wattle plays in sustainable development by considering the environmental/ecological problem of its impact on bio-diversity and the water sources as well as the advantages it has in the process of forest recovery. Secondly notice will be taken of the social advantages the tree has for the inhabitants of rural areas as a provider of building and construction material and firewood, which would otherwise come from the woodlands and/or indigenous forests. The tree also provides in the timber requirements of industry in the form of for instance poles, pulp and extract. Lastly, the article explores the Work-for-Water Programme.


2012 ◽  
Vol 24 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Jerzy Lisek

Winter frost injury of buds on one-year-old grapevine shoots ofVitis viniferacultivars and interspecific hybrids in PolandFollowing the winter of 2009/2010, an assessment of frost damage was carried out on the vines of 40 wine cultivars and 32 table grape cultivars grown in central Poland (Skierniewice, latitude 51° 57' N, longitude 20° 08' E). The minimum winter temperature of -28.1°C was recorded on 26 January 2010. Cultivars were assigned to five classes of different frost tolerance, according to information on the percentage of frozen buds: very resistant (below 1.9%), resistant (2 - 24.9%), medium susceptible (25 - 74.9%), susceptible (75 - 95.9%) and very susceptible (above 96%). The numbers of wine and table cultivars in each class were as follows: very resistant - 5 (wine) and 3 (table), resistant - 2 and 5, medium susceptible - 15 and 10, susceptible - 13 and 9 and very susceptible - 5 and 5. The most tolerant were the ‘Alwood’, ‘Delaware’, ‘Fredonia’ and ‘Zilga’ interspecific hybrids of theVitis labruscanagroup; the ‘Aurore’, ‘Marechal Foch’ and ‘Leon Millot’ hybrids originating fromV. vinifera, V. rupestris, V. ripariaandV. lincecumiiand ‘Sibera’ originating fromV. viniferaandV. amurensis.More than 96% of buds froze on the vines of some interspecific hybrids (‘Arkadia’, ‘Fanny’, ‘Kodrianka’ and ‘Lilla’). ‘Ortega’, ‘Nektar’, ‘Cserszegi Fueszeres’, ‘Riesling’ and ‘Chasselas Dore’ from theV. viniferacultivars showed the best tolerance to frost damage (42.5-62% of frozen buds). The buds of theV. viniferacultivars ‘Acolon’, ‘Dakapo’ and ‘Favorit’ all froze. Plant parts covered with soil and snow were not exposed to significant damage, even in the case of susceptible cultivars.


Diversity ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 207
Author(s):  
Hana Daneck ◽  
Matthias Benjamin Barth ◽  
Martin Geck ◽  
Anna K. Hundsdoerfer

The spurge hawkmoth Hyles euphorbiae L. (Sphingidae) comprises a remarkable species complex with still not fully resolved taxonomy. Its extensive natural distribution range covers diverse climatic zones. This predestinates particular populations to cope with different local seasonally unfavorable environmental conditions. The ability of the pupae to overcome outer frosty conditions is well known. However, the differences between two main ecotypes (‘euphorbiae’ and ‘tithymali’) in terms of the inherent degree of frost tolerance, its corresponding survival strategy, and underlying mechanism have not been studied in detail so far. The main aim of our study was to test the phenotypic exhibition of pupae (as the relevant life cycle stadia to outlast unfavorable conditions) in response to combined effects of exogenous stimuli, such as daylight length and cooling regime. Namely, we tested the turnout of subitan (with fast development, unadapted to unfavorable conditions) or diapause (paused development, adapted to unfavorable external influences and increased resistance) pupae under different conditions, as well as their mortality, and we measured the super cooling point (SCP) of whole pupae (in vivo) and pupal hemolymph (in vitro) as phenotypic indicators of cold acclimation. Our results show higher cold sensitivity in ‘tithymali’ populations, exhibiting rather opportunistic and short-termed cold hardiness, while ‘euphorbiae’ produces a phenotype of seasonal cold-hardy diapause pupae under a combined effect of short daylight length and continuous cold treatment. Further differences include the variability in duration and mortality of diapause pupae. This suggests different pre-adaptations to seasonal environmental conditions in each ecotype and may indicate a state of incipient speciation within the H. euphorbiae complex.


2016 ◽  
Vol 11 (49) ◽  
pp. 4979-4989
Author(s):  
C. Cadori Guilherme ◽  
R. Sanquetta Carlos ◽  
Pellico Netto Sylvio ◽  
Behling Alexandre ◽  
Costa Junior Sergio ◽  
...  

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