Relation between level of autumn dormancy and salt tolerance in lucerne (Medicago sativa)

2018 ◽  
Vol 69 (2) ◽  
pp. 194 ◽  
Author(s):  
Kunyong Huang ◽  
Xiaoxia Dai ◽  
Yiquan Xu ◽  
Shibing Dang ◽  
Tianran Shi ◽  
...  

Experiments were conducted to study the relationship between autumn (fall) dormancy rating (FDR) and salt tolerance of lucerne (alfalfa, Medicago sativa L.). Seeds of eight cultivars with different FDRs (range 2.0–10.2) were germinated in a growth chamber under five concentrations of NaCl (range 0–1.2%). A subordinate function value method was adopted for comprehensive evaluation of salt tolerance of the lucerne cultivars. Seed germination rate and germination potential, and seedling electrolyte leakage, shoot length, root length, fresh weight, root : shoot length ratio, Na+ and K+ concentrations and K+ : Na+ ratio were used as the indices of evaluation. Under 1.2% salt treatment, salt-tolerance ranking of the cultivars was WL656HQ > WL440HQ > WL712HQ > WL525HQ > WL343HQ > WL319HQ > WL363HQ > WL168HQ, with respective FDRs of 9.3, 6.0, 10.2, 8.2, 3.9, 2.8, 4.9 and 2.0. The results of this study show that non-dormant cultivars were generally more salt tolerant than dormant cultivars.

2011 ◽  
Vol 40 (1) ◽  
pp. 113-127
Author(s):  
F. ABDEL-TAWAB ◽  
EMAN FAHMY ◽  
M. EL- NAHRAWY ◽  
WAFAA SHARAWY ◽  
MERVAT SAYED

2014 ◽  
Vol 13 (3) ◽  
pp. 5350-5360 ◽  
Author(s):  
L.Q. Zhang ◽  
Y.D. Niu ◽  
H. Huridu ◽  
J.F. Hao ◽  
Z. Qi ◽  
...  

1977 ◽  
Vol 57 (3) ◽  
pp. 873-881 ◽  
Author(s):  
R. MICHAUD ◽  
T. H. BUSBICE

Alfalfa (Medicago sativa L.) is a highly heterozygous cross-pollinating species, and most breeding efforts have been conducted on noninbred populations. The purpose of this study was to determine whether greater breeding progress could be made by selecting within partly inbred populations rather than within noninbred ones. One hundred and twenty F1 (noninbred) and 120 S1 (partly inbred) plants that were issued from crossing and selfing four alfalfa clones were evaluated for self-fertility. The most self-fertile 10% of the plants from each family were selected in each population. The selected plants within each level of inbreeding were intercrossed to produce an advanced generation in which the effectiveness of the selection was evaluated. Selection increased both self- and cross-fertility in the advanced generation. Selection was more effective at the F1 level than at the S1 level. Fertility was reduced drastically by inbreeding. The average self-fertility of the S1’s was only about 7% of the cross-fertility of their parental clones. An exponential model was proposed to describe the relationship between seed setting and the coefficient of inbreeding in the developing zygote. This model explained 95% of the variation among 11 unselected populations having differing levels of inbreeding.


Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 597 ◽  
Author(s):  
Misganaw Wassie ◽  
Weihong Zhang ◽  
Qiang Zhang ◽  
Kang Ji ◽  
Liang Chen

Alfalfa (Medicago sativa L.) is a valuable forage legume, but its production is largely affected by high temperature. In this study, we investigated the effect of heat stress on 15 alfalfa cultivars to identify heat-tolerant and -sensitive cultivars. Seedlings were exposed to 38/35 °C day/night temperature for 7 days and various parameters were measured. Heat stress significantly reduced the biomass, relative water content (RWC), chlorophyll content, and increased the electrolyte leakage (EL) and malondialdehyde (MDA) content of heat-sensitive alfalfa cultivars. However, heat-tolerant cultivars showed higher soluble sugar (SS) and soluble protein (SP) content. The heat tolerance of each cultivar was comprehensively evaluated based on membership function value. Cultivars with higher mean membership function value of 0.86 (Bara310SC) and 0.80 (Magna995) were heat tolerant, and Gibraltar and WL712 with lower membership function value (0.24) were heat sensitive. The heat tolerance of the above four cultivars were further evaluated by chlorophyll a fluorescence analysis. Heat stress significantly affected the photosynthetic activity of heat-sensitive cultivars. The overall results indicate that Bara310SC and WL712 are heat-tolerant and heat-sensitive cultivars, respectively. This study provides basic information for understanding the effect of heat stress on growth and productivity of alfalfa.


1994 ◽  
Vol 41 (3) ◽  
pp. 159-164 ◽  
Author(s):  
M.M. Al-Khatib ◽  
T. McNeilly ◽  
J.C. Collins

1984 ◽  
Vol 35 (2) ◽  
pp. 239 ◽  
Author(s):  
CL Noble ◽  
GM Halloran ◽  
DW West

Variation existed between plants of the lucerne (Medicago sativa L.) cultivar CUF 101 for dry matter production, shoot number and length, and leaf damage when grown for 70 days under 250 mM NaCl (15 h photoperiod, 20�C day, 10�C night). Salt tolerance evaluation using the criteria percentage leaf damage (percentage of total number of leaves with complete or partial necrosis) and length of the main shoot, isolated plants which showed salt tolerance of reasonably high heritability (h2=0.41). Two generations of recurrent selection for tolerance significantly increased the mean population tolerance without decreasing production under non-saline conditions. While both sodium and chloride concentrations of the shoot were lower in the tolerant than in less tolerant plants, chloride was more closely associated with salt tolerance than sodium. Sodium and chloride concentrations in the roots did not vary with the level of salt tolerance. No association of shoot and root potassium concentration with tolerance was evident. Selection for salt tolerance in lucerne plants using percentage leaf damage of less than 10% as the main criterion should give a rapid response to selection. The efficiency of selection may be increased if selection is based on the efficiency of chloride exclusion from the shoots and/or the level of chloride tolerated by the shoots prior to leaf damage becoming evident.


Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 220 ◽  
Author(s):  
Huifang Cen ◽  
Tingting Wang ◽  
Huayue Liu ◽  
Danyang Tian ◽  
Yunwei Zhang

Alfalfa (Medicago sativa L.) is an important and widely cultivated forage grass. The productivity and forage quality of alfalfa are severely affected by salt stress. Melatonin is a bioactive molecule with versatile physiological functions and plays important roles in response to various biotic and abiotic stresses. Melatonin has been proven efficient in improving alfalfa drought and waterlogging tolerance in recent studies. In our reports, we applied melatonin exogenously to explore the effects of melatonin on alfalfa growth and salt resistance. The results demonstrated that melatonin application promoted alfalfa seed germination and seedling growth, and reduced oxidative damage under salt stress. Further application research found that melatonin alleviated salt injury in alfalfa plants under salt stress. The electrolyte leakage, malondialdehyde (MDA) content and H2O2 content were significantly reduced, and the activities of catalase (CAT), peroxidase (POD), and Cu/Zn superoxide dismutase (Cu/Zn-SOD) were increased with melatonin pretreatment compared to control plants under salt stress with the upregulation of genes related to melatonin and antioxidant enzymes biosynthesis. Melatonin was also involved in reducing Na+ accumulation in alfalfa plants. Our study indicates that melatonin plays a primary role as an antioxidant in scavenging H2O2 and enhancing activities of antioxidant enzymes to improve the salt tolerance of alfalfa plants.


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