Effect of phenotypic recurrent selection on genetic diversity of non-dormant multifoliolate lucerne (Medicago sativa L.) populations

2015 ◽  
Vol 66 (11) ◽  
pp. 1190 ◽  
Author(s):  
A. Odorizzi ◽  
E. M. C. Mamani ◽  
P. Sipowicz ◽  
B. Julier ◽  
J. Gieco ◽  
...  

The nutritional quality of lucerne (alfalfa, Medicago sativa L.) plants correlates positively with the presence of multifoliolate (MF) leaves. Using phenotypic recurrent selection, we developed populations with an increased percentage of MF expression from 6.7% in the original population (C0) to 77.7% in the fourth cycle (C4). The effect of selection on genetic diversity within and among populations was evaluated. The populations C0 and C4 were represented by 40 plants genotyped by using 25 simple sequence repeats (SSR). The number of alleles per locus was large in both C0 and C4, averaging 6.28. The within-population genetic diversity (HE) overall estimation was 0.723 for C0 and 0.726 for C4, the absence of significant difference between the two populations indicating that the genetic diversity was as large in C4 as in C0. The Nei’s population differentiation (GST) overall estimation was 0.013, meaning that only 1.3% of the total genetic diversity was between populations and 98.7% was within populations. An efficient selection process was conducted without any increase in inbreeding or genetic drift.

2019 ◽  
Vol 35 (2) ◽  
pp. 163-178
Author(s):  
Snezana Paskas ◽  
Jelena Miocinovic ◽  
Branislav Vejnovic ◽  
Zsolt Becskei

The study was to conduct to evaluate the chemical composition and nutritive values of feedstuffs (forages and concentrate mixtures) used for dairy goats nutrition in Vojvodina. Samples were collected from six farms, including one organic farm. The results showed that the relative feed values of analyzed forages were in the range of good, medium to lower quality. Average protein content from lowest to highest for investigated forages was: corn silage (Zea Mays) (65.37-82.57g kg??DM), alfalfa haylage (Medicago sativa L.) (159.99-184.17g kg??DM), pasture (185.30g kg?? DM), and alfalfa hay (Medicago sativa L.) (167.48-203.60g kg??DM). The non-fibre carbohydrates and protein content most varied in organic hay samples (cv: 29.25% and 19.09%, respectively). Generally, feedstuffs used in organic nutrition, including organic concentrate, were of lower nutritional quality and moreover contained higher amounts of crude fibre and lignin. Especially, a high source of variation was observed in investigated concentrate mixtures for the crude protein content (p<0.0001), ranged from 135.32 to 209.87g kg??DM. Corn silages also varied substantially in their chemical composition and significant difference (p<0.05) was observed in regard to acid detergent fibre (ADF) and lignin content (ranged: ADF: 242.20-319.24g kg??DM; ADL: 27.98-52.54g kg??DM, respectively). Furthermore, pasture contained the most soluble materials during May and June and their content was related inversely to crude fibre amount. This survey highlights that investigated farms still pay insufficient attention to the quality of the feedstuff. For the development of intensive goat farming, greater emphasis should be placed on using higher quality feedstuffs, as well, standards for feed quality must be considered and established.


1984 ◽  
Vol 64 (1) ◽  
pp. 119-130 ◽  
Author(s):  
NORMAN L. TAYLOR ◽  
PAUL L. CORNELIUS ◽  
ROY E. SIGAFUS

Phenotypic recurrent selection on an annual basis was conducted with zigzag clover (Trifolium medium L.) to determine the efficiency of selection for improved seed and forage yield and the relationships among these characters. Seedlings were exposed to winter temperatures in a cold frame before they were transplanted in a field in the spring. The undesirable types were mowed prior to flowering and the selected plants were allowed to cross. Heads and seeds were harvested from each plant, and after seed threshing and counting, plants were further selected on the basis of numbers of seeds and heads. The effectiveness of four cycles of selection was evaluated over a 2-yr period in an experiment initiated with remnant seed and with management similar to that imposed during the selection process. Recurrent selection was effective in increasing vigor, seeds per head, heads per plant, and seeds per plant. A significant linear increase over cycles was found for each character. Vigor was not correlated with seeds per head, but was correlated with the other characters. The more vigorous plants also exhibited less stand reduction. Data from the two evaluation years were correlated suggesting that materials selected on an annual basis performed similarly to those grown in a 2-yr stand. Although recurrent selection was effective for improving all traits, the rate of change, particularly for seeds per head, was limited. Many more cycles of such selection would be required to change zigzag clover into a useful forage species. It was suggested that the phenotypic recurrent selection program should be continued on an annual basis, but modified if possible to select against the vernalization requirement for flowering which may be associated with poor seedling growth and low aftermath vigor.Key words: Trifolium medium, recurrent selection, vigor, persistance, heads and seeds per plant


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.


Author(s):  
Sebahattin Albayrak ◽  
Mehmet Oten ◽  
Mevlut Turk ◽  
Mehmet Alagoz

The aim of the research was to determine the forage yield and quality of thirty alfalfa (Medicago sativa L.) genotypes. Plots were established in 2014 in Isparta, Turkey, in a randomized complete block design with 3 replicates. Five cuttings were done during the 2015, 2016 and 2017. The dry matter yield (DMY), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL) and relative feed value (RFV) were determined. According to the three years average results, significant differences were determined for all parameters. Alfalfa genotypes viz., Cay-1, Cay-2, Keciborlu-1 and Keciborlu-3 were selected for alfalfa breeding program due to their superior yield and quality features.


1984 ◽  
Vol 64 (3) ◽  
pp. 667-675 ◽  
Author(s):  
L. BELZILE

The effects of cultivars, date and rate of seeding on the yield and quality of alfalfa (Medicago sativa L.) seeded at the end of summer and harvested the year after was studied from 1971 to 1975 on a Kamouraska clay. Seeding in early August gave the best results; seeding should not be carried out after mid-August. Differences between cultivars were more important on the third than on the first cut. Aftergrowth was an important factor on yield during the first year of harvest. Seeding rate did not always affect the yield, but the 6,7 kg/ha rate yielded less than the 13,4 kg/ha rate at the first cut and when the cuts were summed. The combined effects of the three factors studied indicates the importance of the seeding date on the height, cover and yield of alfalfa. Digestibility and crude protein content of the dry matter were affected more by seeding dates than by cultivars. The effect of cultivars on quality was variable and seeding rates had no effect. The variation in forage quality may be attributed to a difference in maturity of the plant at harvest, rather than only to the factors studied.Key words: Medicago sativa L., cultivar, date, rate, yield, quality


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