Flax (Linum usitatissimum L.) responses to chilling and heat stress on flowering and seed yield

Abstract

Gusta, L. V., O'Connor, B. J. and Bhatty, R. S. 1997. Flax (Linum usitatissimum L.) responses to chilling and heat stress on flowering and seed yield. Can. J. Plant Sci. 77: 97-99. The effect of a 5°C chilling treatment at the seedling stage on days to flower, yield and oil quality and quantity was determined for seven cultivars of flax (Linum usitatissimum L.). Three days of chilling delayed flowering in Dufferin, McGregor and NorLin, whereas 5 d of chilling delayed flowering in all cultivars except Andro and Noralta. Seven days of chilling reduced the seed yield of only McGregor, Norlin, NorMan and Vimy. The effect of a 40°C heat stress at the flowering stage on yield and oil composition was determined for the same seven cultivars. A heat stress of 40°C for 3 d reduced the seed yield of NorMan, whereas, a 5 d stress reduced the seed yield of all cultivars except McGregor and Noralta. The composition of the oil was not affected by the heat stress. These results suggest genetic variability exists among flax cultivars for tolerance to chilling and heat stresses. Controlled tests can be used to select superior stress tolerant genotypes. Although flax (Linum usitatissimum L.) is considered to be a cool season crop, air temperature less than 10°C in the spring inhibit both growth and development which can delay flowering (Rowland, G.G., Crop Development Centre, University of Saskatchewan, personal communication). A delay in flowering can result in both reduced oil quantity and quality (lower iodine value) especially if the crop matures under hot and dry conditions (Kenaschuk 1975).It is well established that flax at flowering and seed set is sensitive to heat, particularly to temperatures exceeding 30°C (Dillman and Hopper 1943;Painter et al. 1944;Ford and Zimmerman 1964). Dillman and Hopper (1943) reported high temperatures at the time of flowering reduced both the content of flax oil and iodine numbers. Kraft et al. (1963) found that seed set was reduced at temperatures warmer than 25°C. Partial necrosis of the ovule occurred after 1 d exposure to 31°C and complete necrosis occurred after a 5 d exposure to 31°C. Ford and Zimmerman (1964) reported that a heat period during flowering had a negative effect on boll set. Dybing and Zimmerman (1965) observed increasing temperatures hastened shoot and boll maturity and decreased the numbers of seeds per boll and seed weight. The objectives of this study were to develop methods to screen flax cultivars for both chilling and heat tolerance and to determine if genotypic variation exists within cultivars for resistance to both stresses in regard to flowering, yield, oil content and composition.All studies were conducted over 2 yr using different seed lots from the same location. Each year the experiment was replicated four times in a randomized complete block design. Seven cultivars of flax, Andro, Dufferin, McGregor, NorMan, Noralta, NorLin and Vimy were grown in 13 × 16 cm plastic pots in a mixture of soil: peat: vermiculite (1:1:1). Planting date was the third week of May...

On-farm evaluation of seed yield and oil quality of linseed (Linum usitatissimum L.) in inland areas of Tuscany, Central Italy

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Pollination and floral biology of Adonis vernalis L. (Ranunculaceae) – a case study of threatened species

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Potential Hybridization of Flax with Weedy and Wild Relatives: An Avenue for Movement of Engineered Genes?

“…It does not thrive on sandy soils unless a large supply of moisture is available (Anonymous, 2006). Although flax is considered to be a cool season crop, air temperature below 10°C in the spring may inhibit growth and development, which can delay flowering (Gusta et al, 1997). In a recent study on seed color, seed weight, and seed oil content in several flax accessions, Diederichsen and Raney (2006) revealed that yellow seeded flax had a higher seed weight and oil concentration than brown seeded flax.…”