Characterization of flowering phenology and seed yield in a Pinussylvestris clonal seed orchard in Nebraska

1991 ◽  
Vol 21 (12) ◽  
pp. 1721-1729 ◽  
Author(s):  
Teresa K. Boes ◽  
James R. Brandle ◽  
William R. Lovett
Keyword(s):  
Genetic Diversity ◽  
Seed Yield ◽  
Preliminary Investigation ◽  
Geographic Origin ◽  
Seed Orchard ◽  
Flowering Phenology ◽  
Clonal Seed Orchard ◽  
Sowing Seed ◽  
Seed Crops ◽  
Seed Yields

Forty-two Eurasian Scots pine (Pinussylvestris L.) clones in a Nebraska seed orchard were observed over 3 years for the phenology of pollen release and seed-cone receptivity and for the production of cones and filled seed. A preliminary investigation had indicated that seed yields were less than expected, and nonsynchronous flowering phenology due to wide genetic diversity was considered as a possible cause. The clones were divided into six regions based on geographic origin and analyzed for variation between regions and between clones within regions. Most variation in cones per tree and filled seeds per cone was due to differences between clones. Most variation in weight per seed was due to differences between regions. The order in which clones began releasing pollen and became receptive remained the same from year to year, but the duration of these events differed between years. Results indicated that nonsynchronous flowering phenology due to genetic diversity is not a likely cause of low seed yield. Seed crops (19.3 kg/ha, 97 000 seeds/kg) were not necessarily lower than should be expected, but 90% of a given year's crop was produced by an average of only 26 clones. With the paternal contribution of each clone to the seed crop unknown, collecting and sowing seed separately by clone is recommended.

scholarly journals Ryegrass (Lolium perenne) seed yield response to fungicides a summary of 12 years of field research

2009 ◽  
Vol 62 ◽  
pp. 343-348 ◽  
Author(s):  
M.P. Rolston ◽  
B.L. McCloy ◽  
I.C. Harvey ◽  
R.W. Chynoweth
Keyword(s):  
Seed Yield ◽  
Stem Rust ◽  
Field Research ◽  
Reproductive Development ◽  
Yield Response ◽  
Yield Data ◽  
Seed Fill ◽  
Seed Crops ◽  
Seed Yields ◽  
Green Leaf Area

A summary of seed yield data from 19 fungicide trials in perennial and hybrid ryegrass (Lolium spp) seed crops conducted over a 12 year period is presented Seed yields from the best fungicide treatments were increased on average by 25 in forage ryegrass (390 kg/ha) and 42 in turf ryegrass (580 kg/ha) Seed yield increases were associated with the control of stem rust and/or maintaining green leaf area during seed fill In turf ryegrass (susceptible to stem rust) delaying the first fungicide application until stem rust appeared resulted in seed yields that were not different (P>005) from the untreated experimental controls whereas early fungicide applications from the beginning of reproductive development increased seed yield by between 36 and 42 Fungicide mixes of a triazole plus a strobilurin usually gave higher seed yields than using either fungicide type alone

scholarly journals Fertility Variation and Genetic Diversity in a Clonal Seed Orchard of Cryptomeria japonica

2005 ◽  
Vol 54 (1-6) ◽  
pp. 104-107 ◽  
Author(s):  
K. S. Kang ◽  
Y. A. El-Kassaby ◽  
M. S. Chung ◽  
C. S. Kim ◽  
Y. J. Kang ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Cryptomeria Japonica ◽  
Seed Orchard ◽  
Clonal Seed Orchard ◽  
Fertility Variation ◽  
The Status ◽  
Status Number ◽  
Census Number ◽  
Male Strobilus ◽  
Male Strobili

Abstract Clonal differences in fertility (expressed as the number of female and male strobili) were determined for three consecutive years (2002-2004) in a clonal seed orchard of sugi (Cryptomeria japonica D. Don) in Korea. Fertility varied among clones and among years producing three-year averages of 196 and 652 for female and male strobili per ramet, respectively. Correlation between female and male strobilus production was positive over the three years and statistically significant in 2003, a good flowering year. Based on the observed fertility variation, the status numbers (Ns, measure of genetic diversity) were calculated and varied from 25.6 to 31.7 among the three studied years. On average (pooled), relative status number was 86% of the census number (N). Variation in female fertility was higher than that in male fertility, and this variation was reflected on female and male parents’ status numbers. Pooled Ns estimated from the three years was higher than that for any single year, implying that genetic diversity would increase when seeds collected from different years are pooled.

scholarly journals Integrating fecundity variation and genetic relatedness in estimating the gene diversity of seed crops: Pinus koraiensis seed orchard as an example

2017 ◽  
Vol 47 (3) ◽  
pp. 366-370 ◽  
Author(s):  
Ji-Min Park ◽  
Soon-Ho Kwon ◽  
He-Jin Lee ◽  
Sung-Joon Na ◽  
Yousry A. El-Kassaby ◽  
...  
Keyword(s):  
Genetic Gain ◽  
Genetic Relatedness ◽  
Gene Diversity ◽  
Seed Orchard ◽  
Cumulative Distribution ◽  
Pinus Koraiensis ◽  
Total Production ◽  
Clonal Seed Orchard ◽  
Status Number ◽  
Seed Crops

The genetic gain and gene diversity of seed crops from a 1.5-generation clonal seed orchard of Pinus koraiensis Siebold & Zucc. were estimated under consideration of parental genetic values and fecundity variation. Fecundity variation among clones was estimated for 5 consecutive years (2010–2014) as the sibling coefficient, which was drawn from clonal contribution to the total production of seed conelet. To monitor gene diversity, status number was estimated by the integration of fecundity variation and group coancestry. Group coancestry was calculated as the average of genetic relatedness (coancestry) among orchard clones. The averages of conelet production were high in 2010 and 2011, moderate in 2013 and 2014, and poor in 2012 with a grand mean of 13.7. Correlation analysis showed that good conelet producers consistently gave good production. Cumulative distribution of clonal conelet production was presented as a function of the total conelet yield, and this distribution indicated deviation from the expected clonal equal production. Group coancesrtry was 0.0096, indicating minimal loss of gene diversity. Status number and genetic gain were higher in good than in poor conelet production years, highlighting the importance of fecundity variation in determining the genetic gain and gene diversity of seed orchard crops.

scholarly journals Genetic Gain and Diversity of Orchard Crops Under Alternative Management Options in a Clonal Seed Orchard of Pinus thunbergii

2005 ◽  
Vol 54 (1-6) ◽  
pp. 93-96 ◽  
Author(s):  
Kyu-Suk Kang ◽  
D. Lindgren ◽  
T. J. Mullin ◽  
W.-Y. Choi ◽  
S.-U. Han
Keyword(s):  
Gene Flow ◽  
Genetic Gain ◽  
Seed Orchard ◽  
Pinus Thunbergii ◽  
Management Options ◽  
Pollen Contamination ◽  
Clonal Seed Orchard ◽  
Selective Harvest ◽  
Status Number ◽  
Seed Crops

Abstract Genetic gain and diversity, expressed by status number, of seed crops from a clonal seed orchard of Pinus thunbergii were estimated considering selection, fertility variation and pollen contamination, and compared for different management alternatives (selective harvest, genetic thinning and combination of both options). Management variables included the proportion of clones left after selective harvest and/or genetic thinning. The impact on genetic gain and diversity of seed crops was quantified as a function of the quantity and quality of gene flow from outside the seed orchard. Genetic gain varied with the proportion of selected or thinned clones. Genetic thinning by means of truncation selection of clones resulted in a large decrease in status number, which was accompanied by greater genetic gain than achieved by selective harvest alone. As expected, gene flow from outside the seed orchard greatly increased status number of the seed crop at higher rates of pollen contamination under all management options. The formulae and results of the present study could be used for identifying favorable selection intensity and alternatives for orchard management.

scholarly journals MIRlDS IN 'GRASSLANDS MAKU' LOTUS SEED CROPS: FRIENDS OR FOES?

1983 ◽  
pp. 42-46
Author(s):  
P.T.P. Clifford ◽  
J.A. Wightman ◽  
D.N.J. Whitford
Keyword(s):  
Key Words ◽  
Seed Production ◽  
Seed Yield ◽  
Pod Shattering ◽  
Lotus Seed ◽  
Lotus Pedunculatus ◽  
Seed Crops ◽  
Seed Yields ◽  
Insecticide Control

The need for mirid (Calocoris norvegicus Gmel.) control to improve seed yields of 'Grasslands Maku' lotus seed crops was studied over two seasons on a crop near Lincoln, Canterbury. In 1980 seed yields were increased by 40% to 850 kg/ha by the application of bromophos (500 g a.i./ha) in mid-December to remove a population of 30 mirids/20 net sweeps. In 1981, demetonb-methyl (200 g a.i./haj was applied along with a water only control in mid-November, followed by a blanket spray of bromophos in mid-December. There were two separate effects resulting from the use of metasystox. Although demetondmethyl protection gave a higher seed yield/stem for early-formed flowerheads the pattern was reversed for the later-formed flowerheads because early mirid attack increased flowerhead numbers/stem. Laterformed umbels gave a more concentrated span of flowering, which enhanced better timing of harvest of this crop which is prone to pod shattering. The recommendation is to control mirids only in mid-December using bromophos. an insecticide that is relatively bee safe. Key Words: Seed production, Lotus pedunculatus, mirids, Calocoris norvegicus, insecticide control

Chemical Manipulation of Grass Seed Crops

1985 ◽  
Vol 2 ◽  
pp. 9-14
Author(s):  
J.G. Hampton ◽  
T.G.A. Clemence ◽  
B.L. Mccloy
Keyword(s):  
Seed Yield ◽  
Perennial Ryegrass ◽  
Leaf Tissue ◽  
Yield Potential ◽  
Seed Abortion ◽  
Growth Retardants ◽  
Grass Seed ◽  
Poor Seed ◽  
Seed Crops ◽  
Seed Yields

The seed yield potential established at anthesis in grass seed crops is usually 5-10 times greater than actual seed yields realised at harvest. Losses in seed yield between anthesis and harvest result primarily from the death of fertile tillers and poor seed site utilisation. Lodging has been identified as one of the most important factors reducing seed yields, and the use of growth retardants has significantly increased seed yield in perennial ryegrass and tall fescue. The effects of the growth retardant paclobutrazol on the growth, development and seed yield of perennial ryegrass (Lolium perenne) are presented and discussed. Little is known of the effects of leaf and stem diseases on grass seed yields. Recent research has found that fungicide application can substantially increase seed yield in perennial ryegrass through delaying senescence of leaf tissue. Increased leaf area duration is associated with a reduction in seed abortion, resulting in more seeds per spikelet at harvest. The possibilities for fungicide use in the crop are discussed. Keywords: Seed production, grasses, fertile tillers, seed abortion, growth retardants, paclobutrazol, fungicide, senescence.

scholarly journals Influence of geographic distance and genetic dissimilarity among clones on flowering synchrony in a Teak (Tectona grandis Linn. f) clonal seed orchard

2012 ◽  
Vol 61 (1-6) ◽  
pp. 10-18 ◽  
Author(s):  
N. Lyngdoh ◽  
R. P. Gunaga ◽  
Geeta Joshi ◽  
R. Vasudeva ◽  
G. Ravikanth ◽  
...  
Keyword(s):  
Geographic Distance ◽  
Tectona Grandis ◽  
Seed Orchard ◽  
Flowering Phenology ◽  
Flower Initiation ◽  
Dissimilarity Index ◽  
Flowering Synchrony ◽  
Clonal Seed Orchard ◽  
Genetic Dissimilarity ◽  
Flowering Asynchrony

Abstract Influence of genetic dissimilarity among teak (Tectona grandis Linn. f.) clones on flowering synchrony was studied in a Clonal Seed Orchard (CSO) of teak in Karnataka, Southern India. Flowering phenology was monitored for all the 24 teak clones of the CSO and flowering synchrony between clones was assessed adopting a novel ‘overlap index’. Genetic dissimilarity among these clones was assessed adopting DNA based ISSR (Inter Simple Sequence Repeats) analysis. Large variation in the time of ‘flower initiation’ and of ‘peak flowering initiation’ was observed among the clones belonging to diverse sources, suggesting large asynchronous flowering. Cluster analysis based on ISSR marker indicated that the clones originating from a same source clustered together and there was a clear segregation based on their origin. Correlation analysis revealed a significant negative association between the average Jaccards’s dissimilarity index between pairs of clones and average peak flowering overlap index. Clones from geographically diverse regions had high genetic dissimilarity and also showed high flowering asynchrony within them.

scholarly journals Phalaris and tall fescue seed production: Volunteer control and herbicide tolerance

1999 ◽  
Vol 52 ◽  
pp. 214-217
Author(s):  
K. Reddy ◽  
M.P. Rolston ◽  
W.J. Archie
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Tall Fescue ◽  
Untreated Control ◽  
Herbicide Tolerance ◽  
Good Tolerance ◽  
Phalaris Aquatica ◽  
Second Year ◽  
Seed Crops ◽  
Seed Yields

Experiments in grass seed crops investigated the control of volunteers in phalaris (Phalaris aquatica) and tolerance of phalaris seed crops to four herbicides and tall fescue (Festuca arundiacea) to eight herbicides. Atrazine at 2040 g/ha gave 94% control of volunteer phalaris and both atrazine at 2040 g/ha and ethofumesate at 2000 g/ha showed good tolerance with phalaris seed yields of 760 and 750 kg/ha compared to untreated control which had a seed yield of 620 kg/ha. Tall fescue seed yields showed good tolerance to terbuthylazine at 750 g/ha, prodiamine at 65 g/ha, chlorpropham at 1200 g/ha, diuron at 1800 g/ha and oxyflurofen at 288 g/ha with seed yields of 2580-2730 kg/ha compared to untreated of 2200 kg/ha. In the second year, burn treatments with metolachlor at 1920 g/ha gave 88 % volunteer control with a seed yield of 1380 kg/ha compared with untreated control of 1090 kg/ha.

Effects of herbicides on wallaby grass (Danthonia spp.). 2. Established plants

1994 ◽  
Vol 34 (6) ◽  
pp. 759 ◽  
Author(s):  
GM Lodge ◽  
MG McMillan
Keyword(s):  
Seed Yield ◽  
Dry Matter ◽  
New South ◽  
New South Wales ◽  
Early Spring ◽  
Dry Matter Yield ◽  
Annual Grass ◽  
South Wales ◽  
Seed Crops ◽  
Seed Yields

Three experiments were conducted at Tamworth, New South Wales, in 1990-92 to assess the effects of a range of broadleaf and grass herbicides, 6 rates of glyphosate and paraquat + diquat, and 4 rates of 2,4-D amine and diuron on the phytotoxicity, dry matter yield, inflorescence number, and seed yield of established Danthonia (wallaby grass) plants. Phytotoxicity was scored visually on a 0-5 scale (0, no phytotoxicity; 5, 100%). Danthonia dry matter yields were not affected (P<0.05) by any herbicide tested, except glyphosate applied at 2360 g a.i./ha. Phytotoxicity was highest for the glyphosate treatment (1440 g a.i./ha) in that study. All rates of glyphosate, and paraquat + diquat rates >250 + 150 g a.i./ha reduced (P<0.05) inflorescence number compared with the unsprayed control. Paraquat + diquat had no significant effect on seed yield, but glyphosate rates >360 g a.i./ha reduced (P<0.05) seed yield compared with the control. In 1992, no damage was observed on 2,4-D amine treatments and phytotoxicity scores were low (<2) for all diuron treatments. Danthonia inflorescence numbers and seed yields were higher (P<0.05) on plots mown in early spring than on unmown treatments. The lack of effect of herbicides such as diclofopmethyl, simazine, fenoxaprop-ethyl, and diuron on Danthonia dry matter yield, and the low phytotoxicity, indicated that a range of chemicals may be used on established Danthonia swards to control perennial and annual grass weeds. Seed yield was more affected than dry matter yield by herbicide, and paraquat + diquat should be used in preference to glyphosate on seed crops.

scholarly journals Variation in Platycladus orientalis (Cupressaceae) Reproductive Output and Its Effect on Seed Orchard Crops’ Genetic Diversity

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1429
Author(s):  
Siqian Jiao ◽  
Meiyu Li ◽  
Yuanjiao Zhu ◽  
Shanshan Zhou ◽  
Shiwei Zhao ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Reproductive Output ◽  
First Generation ◽  
Seed Orchard ◽  
Effective Number ◽  
Ecological Value ◽  
Seed Orchards ◽  
Platycladus Orientalis ◽  
Fertility Variation ◽  
Seed Crops

The genetic efficiency of seed orchards is crucial for determining seed crops’ genetic gain and diversity. Platycladus orientalis is a conifer tree of important ecological value in China. Here, we assessed the reproductive output (fertility) variation for 166 clones in a first-generation P. orientalis seed orchard over five years and across three years for each gender (female: 2017, 2018, and 2020 and male: 2017, 2019, and 2021). Fertility variation and genetic diversity parameters were estimated for each gender-year combination. The reproductive output (fertility) variation differed among years, provinces, clones nested within provinces, and ramets within clones. We observed asymmetry in the gender reproductive output and parental imbalance and determined their profound effects on the genetic diversity of these seed crops. The maleness index revealed the existence of female-biased or male-biased clones. When seeds from multiple individuals and years were blended, we found an increase in the effective number of parents (Np) and in genetic diversity (GD), and a reduced fertility variation (Ψ) in the seed orchard. When we set the effective number of parents (Np) to 30, the GD of the seed orchard could be maintained at more than 95%. Thus, achieving genetic diversity balance in seed production can be accomplished through monitoring the fertility variation of orchards and through the utilization of the thereby generated information for the advanced generation of seed orchards.

Sign in / Sign up

Export Citation Format

Share Document