Low temperature emergence potential of short season corn hybrids grown under controlled environment and plot conditions

One important reason for limited progress in selecting corn (Zea mays L.) with superior cold tolerance during germination and early growth is the unpredictable occurrence of cold, wet test springs. Breeders need an efficient laboratory test paralleling field emergence under such climatic conditions. Laboratory screening data from 30 corn hybrids with under 2400 corn heat unit ratings were compared to field emergence data in Atlantic Canada to evaluate the usefulness of a laboratory test as an indicator of cold tolerance. Hybrids were ranked by mean percent emergence using 1985–1989 field data collected from seven locations in the Atlantic region. From daily observations on seed germinated in a germinator at 11 °C, mean times to 50% root and coleoptile initiation, and 1-cm coleoptile were calculated using probit analyses. Field emergence ranked from 1 (highest percent) to 30 was compared to ranking of time to 50% 1-cm coleoptile in the laboratory (one represented most rapid growth). Of the top 15 hybrids (by 1-cm coleoptile), 11 fell in the top half of the hybrids ranked by field emergence. Removal of hybrids with low numbers of field observations, all made during the unusually warm spring of 1989, improved the comparison. These results indicate that time to 50% production of a 1-cm coleoptile is a useful screening parameter to select corn hybrids with superior cold tolerance during germination and early growth.Key words: Corn, maize, low temperature tolerance, emergence

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Cold tolerance in rice varieties at different growth stages

Crop and Pasture Science ◽

10.1071/cp09006 ◽

2009 ◽

Vol 60 (4) ◽

pp. 328 ◽

Cited By ~ 34

Author(s):

C. Ye ◽

S. Fukai ◽

I. Godwin ◽

R. Reinke ◽

P. Snell ◽

...

Keyword(s):

Low Temperature ◽

Cold Tolerance ◽

High Elevation ◽

Temperature Tolerance ◽

Seedling Stage ◽

Growth Stages ◽

Rice Varieties ◽

Low Temperature Tolerance ◽

Wide Range ◽

Different Growth Stages

Low temperature is a common production constraint in rice cultivation in temperate zones and high-elevation environments, with the potential to affect growth and development from germination to grain filling. There is a wide range of genotype-based differences in cold tolerance among rice varieties, these differences often reflecting growth conditions in the place of origin, as well as breeding history. However, improving low temperature tolerance of varieties has been difficult, due to a lack of clarity of the genetic basis to low temperature tolerance for different growth stages of the rice plant. Seeds or plants of 17 rice varieties of different origins were exposed to low temperature during germination (15°C), seedling, booting, and flowering stages (18.5°C), to assess their cold tolerance at different growth stages. Low temperature at the germination stage reduced both the percentage and speed of germination. Varieties from China (B55, Banjiemang, and Lijianghegu) and Hungary (HSC55) were more tolerant of low temperature than other varieties. Most of the varieties showed moderate levels of low temperature tolerance during the seedling stage, the exceptions being some varieties from Australia (Pelde, YRL39, and YRM64) and Africa (WAB160 and WAB38), which were susceptible to low temperature at the seedling stage. Low temperature at booting and flowering stages reduced plant growth and caused a significant decline in spikelet fertility. Some varieties from China (B55, Bangjiemang, Lijiangheigu), Japan (Jyoudeki), the USA (M103, M104), and Australia (Quest) were tolerant or moderately tolerant, while the remaining varieties were susceptible or moderately susceptible to low temperature at booting and flowering stages. Three varieties from China (B55, Lijianghegu, Banjiemang) and one from Hungary (HSC55) showed consistent tolerance to low temperature at all growth stages. These varieties are potentially important gene donors for breeding and genetic studies. The cold tolerance of the 17 rice varieties assessed at different growth stages was correlated. Screening for cold tolerance during early growth stages can therefore potentially be an effective way for assessing cold tolerance in breeding programs.

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Tetraploidy enhances the cold-resistance in yellow kiwifruit (Actinidia chinensis)

10.21203/rs.2.21136/v1 ◽

2020 ◽

Author(s):

Yipei Li ◽

Xiaozhen Liu ◽

Zhou Wei ◽

Zhimin Zhang ◽

Wen Bian ◽

...

Keyword(s):

Survival Rate ◽

Low Temperature ◽

Cold Tolerance ◽

Regulatory Networks ◽

Temperature Tolerance ◽

Temperature Treatment ◽

Actinidia Chinensis ◽

Low Temperature Tolerance ◽

Low Temperature Treatment ◽

Cold Tolerant

Abstract Yellow kiwifruit ( Actinidia chinensis ) is highly susceptible to severe weather, such as low temperature and frost, which may affect the production in the coming year. And the cold-resistant mechanism of kiwifruit associated with gene regulation is poorly investigated. To botain cold-resistant germplam, to provide insight into the causes of differences in low temperature tolerance due to ploidy and to better understand cold-adaptive mechanisms in tetraploid kiwifruit, the diploid yellow kiwifruit ‘SWFU03’ and its tetraploid plantlets were subjected to cold-tolerant screening with L-hydroxyproline (L-Hyp) and low temperature, the selected ones were then analyzed by transcriptome data and confirmed by RT-qPCR. The results showed that the survival rate of tetraploid plants was 62.22% when treated with 8 mmol/L L-Hyp for 30 days, while all the diploid ones died. After treated with 0°C for 12 h, then at room temperature for seven days, the survival rate of tetraploid plantlets was 42.22%, while all diploidy died. Hence, cold tolerance of the tetraploid plantlets was stronger than that of the diploid genotypes. Using these two screening systems, 126 cold-resistant tetraploid tissue culture plantlets were obtained. A total of 1630 differentially expressed genes (DEGs) were identified, of which 619 were up-regulated and 1011 were down-regulated in the low temperature treatment goup. The DEGs enriched in the cold-tolerance related pathways mainly included plant hormone signal transduction, and starch and sucrose metabolism pathway. RT-qPCR analysis confirmed the expression levels of eight up-regulated genes in these pathways in the cold-resistant mutants. In conclusion, this study has identified cold-resistant yellow kiwifruit plantlets and cold-tolerance related genes. Moreover, the dataset got in this study advances our knowledge of the cold-adaptive genes in the regulatory networks and leads to understand the cold tolerance mechanisms in the tetraploid yellow kiwifruit.

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LOW-TEMPERATURE TOLERANCE OF SWITCHGRASS (Panicum virgatum L.)

Canadian Journal of Plant Science ◽

10.4141/cjps90-131 ◽

1990 ◽

Vol 70 (4) ◽

pp. 1091-1096 ◽

Cited By ~ 22

Author(s):

H. J. HOPE ◽

A. McELROY

Keyword(s):

Low Temperature ◽

Cold Tolerance ◽

Panicum Virgatum ◽

Temperature Tolerance ◽

Cold Hardening ◽

Low Temperature Tolerance ◽

Plastic Bags ◽

Matter Production ◽

Panicum Virgatum L ◽

Two Populations

Dry matter production from temperate pasture species is typically very low during midsummer. Switchgrass (Panicum virgatum L.) is being investigated as an alternative pasture species to overcome this problem. We studied two populations over 3 yr to determine if they had sufficient cold tolerance to be used in these areas. Populations selected from cv. Pathfinder were grown in plots at Ottawa and sampled from September to late November in 1985–1987. Each fall, samples were dug at intervals of 2 or 4 wk, the tops and roots trimmed back, then placed in plastic bags in a programmed freezer to determine the temperature at which 50% of the plants were killed (LT50). Percent crown moisture was also measured in the falls of 1985 and 1986. Prior to the onset of cold hardening in September, the two switchgrass populations had LT50 values of −4 °C. Slow cold-hardening occurred to the end of September, followed by a very rapid increase in cold tolerance to −18 °C at the end of October. During November, the rate of hardening decreased and cold tolerance came to a plateau of −19 to −22 °C by the end of the month. The same range has been reported for winter hardy cultivars of timothy and alfalfa. Crown moisture decreased to a plateau several weeks before LT50 values indicating that moisture is of questionable use as an indicator of cold tolerance in switchgrass. Good cold tolerance in switchgrass combined with superior survival during the severe winter of 1982/1983 and vigorous regrowth from overwintering rhizomes lead us to believe that winter hardy cultivars for central and eastern Ontario could be selected from this material.Key words: Switchgrass, Panicum virgatum L., low temperature tolerance, winter survival, forage plant

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POPULATION VARIATION IN LOW-TEMPERATURE TOLERANCE OF ACER SACCHARINUM

HortScience ◽

10.21273/hortsci.30.2.189b ◽

1995 ◽

Vol 30 (2) ◽

pp. 189b-189

Author(s):

Paul E. Cappiello ◽

John E. Preece

Keyword(s):

Low Temperature ◽

Cold Tolerance ◽

Temperature Tolerance ◽

Population Variation ◽

Native Range ◽

Acer Saccharinum ◽

Low Temperature Tolerance ◽

Single Clone ◽

The Relationship

A single clone of Acer saccharinum was selected and propagated from each of 15 provenances across the plant native range. The clones were field grown in Carbondale, Ill., during the study period. Plants were sampled during Winter 1992-93 and 1993-94 and assayed for low-temperature tolerance. During both winters, plants exhibited greatest variation in tolerance around the November and April sampling dates. In midwinter, there was little variation observed and 13 of 15 clones were tolerant to at least -40C. The relationship among Acer saccharinum provenance and cold tolerance curves will be discussed.

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