EARLY SEEDLING VIGOUR AND SEED WEIGHT IN RELATION TO BREEDING IN SMOOTH BROMEGRASS, BROMUS INERMIS LEYSS.

1960 ◽  
Vol 40 (2) ◽  
pp. 268-280 ◽  
Author(s):  
W. E. Tossell

Variability in early seedling vigour was studied in polycross progenies from highly selected plants rated as good in other agronomic characters and in open-pollinated progenies from previously unselected So plants. Differences were found in both groups in rate and per cent emergence, and in height and vigour at 28 days. Considering the variability observed in these characters and the favourable associations found, it appears that early seedling vigour in bromegrass can be improved by selection within the species.Seed weight was closely associated with early seedling vigour. Plants differed widely in seed weight, and in breeding for early seedling vigour it appears that most rapid progress can be made by screening breeding material for seed weight. Because seed weight did not account for all of the differences among progenies in seedling vigour, progenies from high seed weight plants or families should be subjected to a seedling vigour test to further select for this character. The close relationship found between greenhouse and field trials indicates that at least the initial screening can be done in the greenhouse.

1960 ◽  
Vol 40 (1) ◽  
pp. 21-28 ◽  
Author(s):  
J. E. Winch ◽  
W. E. Tossell

Higher seed yields of Redon red clover were produced from the aftermath following an early hay crop than from the first crop itself. Red clover-timothy mixtures produced more hay in June and more seed from the aftermath than did pure stands of red clover or red clover-bromegrass mixtures. Seeding rates of 3, 6, 9 and 12 lb. per acre had no effect on red clover seed yield but did affect hay yield. With 2 lb. of timothy, no increase in hay yield was obtained with red clover seeding rates above 6 lb. per acre.Red clover alone produced more seed per acre than red clover-timothy or red clover-brome mixtures when seed was harvested from the first crop. First-crop seed was higher in seed weight than second-crop seed and this was reflected in increased early seedling vigour.


2020 ◽  
Vol 49 (2) ◽  
pp. 357-365
Author(s):  
Hemender Tanwar ◽  
Shikha Yashveer ◽  
Vijay Pal Sangwan ◽  
Sushma Sharma ◽  
Sonali Sangwan ◽  
...  

Thirty four pearl millet restorer lines were evaluated on the basis of nine seed vigour traits and molecular analysis was done with 55 SSRs to study the genetic divergence among them. Cluster analysis based on seed vigour parameters revealed the considerable amount of variability and all genotypes were divided into six clusters. Furthermore, a set of 39 SSRs, selected after initial screening of 55, amplified 226 alleles with a mean of 5.84 alleles per locus. The highest polymorphic information content (PIC) value obtained was for PSMP 2084 (0.88) with a range of 0 to 0.88 and average PIC of 0.558. Neighbor joining tree based on molecular data differentiated all the genotypes into two major groups. The grouping based on both approaches can help breeders to use the studied material in further breeding for improvement of germination potential and early seedling vigour of pearl millet.


Crop Science ◽  
1970 ◽  
Vol 10 (5) ◽  
pp. 539-542 ◽  
Author(s):  
R. P. Knowles ◽  
D. A. Cooke ◽  
E. Buglass

1980 ◽  
Vol 60 (4) ◽  
pp. 1163-1170 ◽  
Author(s):  
R. P. KNOWLES

Seedlings of a group of North American cultivars of smooth bromegrass were examined at the three-leaf stage for pubescence under greenhouse conditions. Southern strains showed 90–98% strongly pubescent seedlings while northern strains had 60–70% strongly pubescent seedlings. Saratoga, although considered southern in type, was less pubescent than all other cultivars except Polar. The degree of pubescence was greater in spring and early fall plantings than in winter plantings, indicating that pubescence depends on good light and temperature conditions. Strains nearly pure for strong pubescence were formed by repeated cycles of mass selection. Few inbred lines showed uniformity for pubescent or smooth seedlings. Pure-breeding smooth stocks were more difficult to produce than highly pubescent strains. Controlled crosses showed partial dominace for pubescence and little difference between reciprocals. Adjacent plantings of pubescent and smooth seedling stocks showed as much as 45% off-type seedlings from seed produced at the interface of plots. Contamination declined to 10% or less at 10 m from the border.


1985 ◽  
Vol 65 (3) ◽  
pp. 787-791
Author(s):  
H. A. BURITY ◽  
B. E. COULMAN ◽  
M. A. FARIS

A greenhouse experiment has shown that total nitrogenase activity of alfalfa (Medicago sativa L.) is not significantly affected when grown in association with timothy (Phleum pratense L.), smooth bromegrass (Bromus inermis Leyss) or orchardgrass (Dactylis glomerata L.) except after initial harvest when decreased alfalfa activity was associated with smooth bromegrass or orchardgrass. It was concluded that mixed cultures of alfalfa with timothy, smooth bromegrass or orchardgrass have no effect on alfalfa N2 fixation. The results also suggest the occurrence of N transference from alfalfa to associated grasses. It is speculated that this transfer is not primarily due to the death of roots and nodule tissue (after harvest), but involves some degree of N excretion during the period before initial harvest.Key words: Alfalfa-grass mixtures, N2-fixation, nodule activity, N-transference


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