scholarly journals Male and Female Fertility of Loosestrife (Lythrum) Cultivars

1993 ◽  
Vol 118 (6) ◽  
pp. 851-858 ◽  
Author(s):  
Neil O. Anderson ◽  
Peter D. Ascher

Male and female fertility, seed germination, and progeny fertility were used to determine cultivar fertility in species of Lythrum. One short-, 11 mid-, and six long-styled cultivars were included in this study. Duplicates of several cultivars from different nurseries and three unknown cultivars from Minnesota gardens were also collected. Plants from 17 Minnesota and one Wisconsin population of L. salicaria served as fertile male and/or female testers. Pollen stainability (usually 100%) showed low levels of male gamete abortion. Pollen size within and among anther type varied widely; possible 2n gametes were present in primarily the short- and mid-anther morphs. Seed production per capsule from legitimate cross-pollinations, using cultivars as male parents with Minnesota or Wisconsin female testers, averaged 48 ± 36 across style morphs. Cultivars differed as males, as did anther morphs. With female fertility tests, seed set per capsule ranged from zero to 152 and averaged 54 ± 40 in legitimate pollinations (i.e., pollinations between stamen and styles of the same length). Seed set for other crosses showed similar trends. Only `Morden Gleam' produced no seed with all legitimate pollinations, although illegitimate selfs or interspecific crosses produced seed. Seed from legitimate crosses of L. salicaria × cultivars had 30% to 100% germination. Common male and female parents within each legitimate crossing group were not significantly different. This study showed that the cultivars are highly fertile when used as male or female parents with wild purple loosestrife, native species (L. alatum Pursh.), or other cultivars. Thus, cultivars grown in gardens could serve as pollen or seed sources for the continued spread of purple loosestrife. The implications of cultivar fertility, especially interspecific F1 hybrids, is discussed in relation to the spread of noxious weeds in wetlands.

2021 ◽  
Vol 140 ◽  
pp. 111448
Author(s):  
Hanan Khaled Sleiman ◽  
Jeane Maria de Oliveira ◽  
Guilherme Barroso Langoni de Freitas

1986 ◽  
Vol 64 (2) ◽  
pp. 282-291 ◽  
Author(s):  
V. Kaul ◽  
J. L. Rouse ◽  
E. G. Williams

Early events in the embryo sac of Rhododendron kawakamii and R. retusum have been studied after compatible self-pollinations and eight interspecific crosses, using sectioned ovaries, pistil squashes, and seed-set data. Ovules of Rhododendron kawakamii and R. retusum are anatropous, unitegmic, and tenuinucellate, with a typical eight-nucleate, seven-celled embryo sac. Fertilization normally occurs 4–5 days after pollination. The zygote lays down a callose wall but remains undivided during the first 13–15 days after pollination. The primary endosperm nucleus divides soon after fertilization, and development is cellular ab initio. Crosses of R. kawakamii (♂) with R. santapaui and R. retusum and crosses of R. retusum (♂) with R. kawakamii, R. santapaui, R. ovatum, and R. tashiroi showed apparently normal fertilization in a majority of ovules entered by pollen tubes. In crosses of R. kawakamii (♂) with R. quadrasianum and Kalmia latifolia entry of pollen tubes into ovules was delayed and frequently abnormal. Apart from compatible self-pollinations of R. kawakamii an R. retusum, only the cross of R. kawakamii (♂) with R. santapaui produced healthy seedlings. Of the remaining seven interspecific crosses only three showed significant embryo development in control pistils left to mature in situ. Similarities and differences in the breeding behaviour of R. kawakamii and R. retusum are discussed with reference to their taxonomic grouping within subsection Pseudovireya.


2004 ◽  
Vol 83 (8) ◽  
pp. 1253-1259 ◽  
Author(s):  
R.L. Sapp ◽  
R. Rekaya ◽  
I. Misztal ◽  
T. Wing

Epidemiology ◽  
2000 ◽  
Vol 11 (6) ◽  
pp. 700-705 ◽  
Author(s):  
Michael Joffe ◽  
Isobel Barnes

2015 ◽  
Vol 64 (1-6) ◽  
pp. 91-99 ◽  
Author(s):  
R. Kamalakannan ◽  
M. Varghese ◽  
J.-M. Park ◽  
S.-H. Kwon ◽  
J.-H. Song ◽  
...  

Abstract Growth and reproductive traits were assessed in seed stands of two native Indian tree species Tamarindus indica and Azadirachta indica. Positive correlation between growth (height and GBH) and reproductive traits (male and female contribution) were found in both species. Fertility was estimated from the flower and fruit production of individuals. Based on the fertility variation among individuals, parental balance, femaleness index and status number (Ns) were determined. The option of equal seed collection among individuals was also considered for estimating Ns. The percentage of fertile trees was higher in the high flowering year in both species. The best male contributing individuals also showed high female contribution (fruit production). The parental contribution in seed stands showed high deviation from expectation; 20% individuals contributed about 70% of male and female gametes in both species. Femaleness index showed that female and male contribution of individual tree was more balanced in the good flowering year, compared to the poor year. Coefficient of variation in male and female fertility was higher in the low flowering year resulting in high fertility variation among individuals and low status number. In T. indica, the female contribution was less variable compared to that of male fertility whereas in A. indica the female fertility variation was higher than that of male fertility. The relative status number (Nr = Ns/N) of the stands was lower for male and female fertility compared to the combined (male and female) fertility of individual trees.


2016 ◽  
Vol 59 (1) ◽  
pp. 9-17 ◽  
Author(s):  
F. Ghafouri-Kesbi ◽  
D. R. Notter

Abstract. Very little is known about the genetic aspects of sexual dimorphism of body weight in domestic sheep, and therefore this study was conducted to quantify the genetic basis of sexual dimorphism for early-growth-related traits in Afshari lambs. Traits evaluated included birth weight (BW), weaning weight (WW), and growth rate (GR) in male and female lambs. Male lambs were 6.6 % heavier at birth, had 14.4 % higher preweaning growth rates and were 16.0 % heavier at weaning compared to female lambs. Levels of sexual-size dimorphism (SSD), expressed as the ratio of male to female means, for BW, WW and GR were 1.07, 1.14 and 1.15, respectively, which indicated low levels of SSD in the traits studied. Fixed effects of year of birth and type of birth interacted with sex effects, with greater variability in birth and weaning weights among years and birth types in male lambs, suggesting greater environmental sensitivity in the males. Bivariate animal models and restricted maximum likelihood (REML) procedures were used to estimate phenotypic variances and their genetic and non-genetic components in male and female lambs. Estimates of the direct heritability (h2) and additive coefficient of variation (CVA) for BW were higher in males. However, for WW and GR, heritability estimates were higher in females. In contrast, whereas the contribution of maternal permanent environmental effects (c2) to variation of BW was higher in females, for WW and GR higher estimates of c2 were observed in males. Respective genetic and maternal permanent environmental correlations between records on males and females were 0.986 and 0.723 for BW, 0.995 and 0.983 for WW, and 0.995 and 0.966 for GR, indicating possible sexual dimorphism only for maternal effects on BW. Based on an approximate 95 % confidence interval, none of the observed differences in variance components between sexes differed from zero and none of the observed genetic or maternal correlations differed from 1.0, indicating no need or opportunity for sex-specific selection strategies.


Weed Science ◽  
1998 ◽  
Vol 46 (3) ◽  
pp. 313-317 ◽  
Author(s):  
R. S. Zemetra ◽  
J. Hansen ◽  
C. A. Mallory-Smith

Jointed goatgrass is a major weed in the wheat-producing areas of the western U.S. It shares the D genome with wheat, and interspecific hybrids between the two species occur in the field. The objective of this research was to determine if wheat X jointed goatgrass hybrids could serve to transfer genes from wheat to jointed goatgrass. A backcrossing program was initiated in the greenhouse between wheat X jointed goatgrass hybrids and either jointed goatgrass or wheat to determine the potential for seed set and the restoration of self-fertility. Seed was set by backcrossing with either species as the recurrent parent. Female fertility increased from 2% in the hybrid to 37% in the BC2 plants with jointed goatgrass as the recurrent parent. Partial self-fertility was restored in the second backcross (BC2) generation using jointed goatgrass as the recurrent parent. This indicates that genes could be transferred between wheat and jointed goatgrass after only two backcrosses. The number of bivalents observed in the plants during meiosis appeared to be key to increasing female fertility and self-fertility. Based on the results of this study, it is possible for genes to move from wheat to jointed goatgrass. Any release of a herbicide-resistant wheat should be accompanied by a management plan that would minimize the potential for gene movement between these species.


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