Safflower Winter Survival and Selection Response Relates to Fall Growth Morphology and Acclimation Capacity

Abstract

Fall‐planted safflower (Carthamus tinctorius L.) offers potentially higher yield than spring‐sown types. Yet winter survival in relation to fall growth and physiological aspects of acclimation has not been determined. Our objectives were (i) to determine the relationship between fall growth and winter survival in safflower, (ii) to assess if selection improved winter survival, and (iii) to determine if water relations and membrane leakage distinguished safflower varying in winter survival. Fall growth, leaf water relations, and leaf membrane leakage were measured in fall 2004 and 2005 at Pullman and Central Ferry, WA, and winter survival was determined. Average minimum winter temperatures were 1.0°C at Central Ferry and −3.9°C at Pullman, with extremes of −7.2°C at Central Ferry and −19.5°C at Pullman. For the 21 accessions evaluated, low fall plant habit was required for survival, but survival also varied substantially among low‐habit types. Two cycles of recurrent mass selection on five low‐habit types improved winter survival from 21 to 59% at Central Ferry and from 8 to 18% at Pullman. The highest survival was for BJ‐27 after two selection cycles, averaging 90% at Central Ferry and 38% at Pullman. Accession BJ‐27 maintained higher leaf pressure potential during fall acclimation in 2004–2005 and in 2005–2006 had higher pressure potential and membrane stability on the 8 January sampling than less‐hardy types. The results show that both low habit and physiological acclimation capacity are needed for high winter survival in safflower.

Yield and Yield Components of Winter‐Type Safflower

“…Winter types PI 651878, PI 651879, and PI 651880 were developed as outlined by Johnson and Li (2008b) at the USDA-ARS Western Regional Plant Introduction Station, Pullman, WA, and released by USDA-ARS in 2007. An additional winter type, PI 405985 (Auld et al, 1983;Johnson et al, 2006;Johnson and Li, 2008a) from Iran, was used in mass selection under winter conditions as described by Johnson and Li (2008b) and documented in the Germplasm Resources Information Network as W6 39446.…”

“…As a result, winter survival has been associated with a long rosette period (Yazdi-Samadi and Zali, 1979), and genotypes with a prolonged rosette period usually have increased cold tolerance and are considered winter types (Ghanavati and Knowles, 1977). Johnson et al (2006) and Johnson and Li (2008a) showed that winter survival was related to low plant height or prostate habit associated with the rosette stage in the fall, but genetic variation in physiological acclimation capacity was also critical to improve winter survival. Johnson et al (2006) and Johnson and Li (2008a) showed that winter survival was related to low plant height or prostate habit associated with the rosette stage in the fall, but genetic variation in physiological acclimation capacity was also critical to improve winter survival.…”

“…Yet a clear distinction between rosette and non-rosette habit can be arbitrary and is infl uenced by genotype and environmental conditions and heritable genetic traits (Zimmerman, 1976;Zimmerman and Buck, 1977). Johnson et al (2006) and Johnson and Li (2008a) showed that winter survival was related to low plant height or prostate habit associated with the rosette stage in the fall, but genetic variation in physiological acclimation capacity was also critical to improve winter survival. Comparing survival of winter and spring types originating in Iran, Yazdi-Samadi and Zali (1979) found a general survival and seed production advantage for fall-planted winter-type saffl ower, but spring types were superior with spring plantings.…”

“…In the Inland Pacifi c Northwest of the United States, plants with overwintering capacity were selected within three accessions originating in China and released as winter-type saffl ower germplasm by Johnson and Li (2008b). Johnson and Li (2008a) also observed a promising winter hardy type from Iran originally identifi ed in winter screening by Auld et al (1983). The objective this research was to compare seed production and yield components of these winter types and spring cultivars under both fall and spring seeding regimes.…”

A Vernalization Response in a Winter Safflower (Carthamus tinctorius) Involves the Upregulation of Homologs of FT, FUL, and MAF

“…Two safflower varieties were used in this study: ‘winter hardy’ C311, known to survive extended cold periods (including overwintering under snow) and ‘spring’ S317, which is a widely grown commercial cultivar ( Wood et al, 2018 ). C311 was sourced from US Department of Agriculture Genetic Resources Information Network (PlantID WSRC03, Johnson and Dajue, 2008 ). Prior to more detailed analysis of flowering time in growth cabinets, S317 and C311 were cultivated in parallel in a small experimental plot at CSIRO Black Mountain site (alluvial soil) in late spring.…”