Cytogenetics off interpopulation Cuphea lanceolata hybrids

Genome ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 1148-1152
Author(s):  
M. Shajahan Ali ◽  
Steven J. Knapp

Cuphea lanceolata Ait. (Lythraceae) is an annual diploid (x = 6) with medium-chain fatty acid rich seed oils. Wild C. lanceolata populations are classified as C. lanceolata f. silenoides or C. lanceolata f. lanceolata on the basis of flower pigment differences. Although these taxa are taxonomically close, their interfertility has not been demonstrated. We describe meiotic phenomena underlying the sterility of hybrids between C. lanceolata f. silenoides (LNS-43) and C. lanceolata f. lanceolata (LNC-78) populations. We assayed metaphase and anaphase I microsporocytes of the parent and hybrid populations. The hybrids were female and male sterile. The mean percentage of stainable pollen was 94.9% for the parents and 1.1% for the hybrids. Chromosomes paired and disjoined normally in the parents (LNS-43 and LNC-78) and abnormally in the hybrids (LNS-43 × LNC-78 and LNC-78 × LNS-43). Univalents, unequal chromosome distributions, and laggards were observed in the hybrids. The mean number of univalents per cell was 0.00 for the parents and 5.95 for the hybrids, the mean number of bivalents per cell was 6.00 for the parents and 1.51 for the hybrids, and the mean number of chiasmata per cell was 9.19 for the parents and 4.04 for the hybrids. The most frequently observed (75%) anaphase I chromosome distribution for the hybrids was 7:5:0 (pole–pole–laggards). The genome affinities of the hybrids were half those of the parents (a mean of 0.5 for the hybrids as opposed to 1.0 for the parents). Although C. lanceolata f. silenoides and C. lanceolata f. lanceolata freely hybridize, their progeny are sterile, and the genetic diversity of LNC-78, and perhaps of C. lanceolata f. lanceolata as a whole, cannot be accessed through hybrids with C. lanceolata f. silenoides or C. viscosissima.Key words: Lythraceae, Cuphea, medium-chain fatty acids, interspecific hybrids, meiosis.

Planta ◽  
2002 ◽  
Vol 215 (5) ◽  
pp. 847-854 ◽  
Author(s):  
Burkhardt Schütt ◽  
Amine Abbadi ◽  
Brigitte Loddenkötter ◽  
Monika Brummel ◽  
Friedrich Spener

HortScience ◽  
2009 ◽  
Vol 44 (6) ◽  
pp. 1534-1537 ◽  
Author(s):  
Joshua H. Kardos ◽  
Carol D. Robacker ◽  
Michael A. Dirr ◽  
Timothy A. Rinehart

The genetic diversity among H. macrophylla (Thunberg) Seringe taxa is limited as a result of the restricted native distribution and multiple breeding programs that used the same taxa and targeted similar breeding goals. This study assessed the compatibility of interspecific crosses between Hydrangea macrophylla and H. angustipetala Hayata as a source of genetic diversity. Two lacecap cultivars of H. macrophylla, ‘Lady in Red’ and Midnight Duchess® (‘HYMMAD II’), were compatible with H. angustipetala. Hybridity of progeny was confirmed by simple sequence repeat markers and morphological comparisons. Some hybrids had red- or purple-pigmented stems, which are characteristic of ‘Lady in Red’ or Midnight Duchess®, respectively. All hybrids had white lacecap inflorescences. Some of the hybrid flowers were fragrant. Winter leaf retention of the hybrids ranged from deciduous to semievergreen. Male fertility of progeny was evaluated by fluorescein diacetate staining of pollen. ‘Lady in Red’, Midnight Duchess®, and H. angustipetala had 62%, 58%, and 79% stainable pollen, respectively, whereas the ‘Lady in Red’ × H. angustipetala and Midnight Duchess® × H. angustipetala hybrids had means of 48% and 47% stainable pollen, respectively. Selected progeny were used to develop F2 and BC1 populations. The interspecific hybrids produced in this study were attractive, fertile plants that are being used in further breeding to develop new cultivars.


Genetics ◽  
2002 ◽  
Vol 161 (3) ◽  
pp. 1269-1278 ◽  
Author(s):  
Bernhard Haubold ◽  
Jürgen Kroymann ◽  
Andreas Ratzka ◽  
Thomas Mitchell-Olds ◽  
Thomas Wiehe

Abstract Arabidopsis thaliana is a highly selfing plant that nevertheless appears to undergo substantial recombination. To reconcile its selfing habit with the observations of recombination, we have sampled the genetic diversity of A. thaliana at 14 loci of ~500 bp each, spread across 170 kb of genomic sequence centered on a QTL for resistance to herbivory. A total of 170 of the 6321 nucleotides surveyed were polymorphic, with 169 being biallelic. The mean silent genetic diversity (πs) varied between 0.001 and 0.03. Pairwise linkage disequilibria between the polymorphisms were negatively correlated with distance, although this effect vanished when only pairs of polymorphisms with four haplotypes were included in the analysis. The absence of a consistent negative correlation between distance and linkage disequilibrium indicated that gene conversion might have played an important role in distributing genetic diversity throughout the region. We tested this by coalescent simulations and estimate that up to 90% of recombination is due to gene conversion.


2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 203-204
Author(s):  
Analicia J Swanson ◽  
Jorge Y Perez-Palencia ◽  
Crystal L Levesque ◽  
Amanda Hesse

Abstract A total of 38 mixed parity sows were used from 28-d of gestation until weaning to determine the effects of medium chain fatty acids (MCFA) in sow and nursery pig diets on litter characteristics and growth performance. On 28-d of gestation, sows were blocked by parity and body weight (BW), and allotted to either a control diet (UNSUP) or a control diet plus 0.3% inclusion of DaaFit Plus (MCFA) fed during gestation and lactation. At weaning, piglets (n=432) were allocated in a 2x2 factorial based on maternal diet (UNSUP or MCFA) and post-weaning diet (UNSUPnurs or MCFAnurs) in a 3-phase nursery pig feeding program lasting 42 days. Individual piglets were weighed at birth, 7-d, at weaning and every 2 weeks post-weaning. A flu outbreak occurred during the latter part of gestation leading to high overall stillborn rate (11%). There was no impact of MCFA supplementation on sow performance (P>0.14). During the suckling period, MCFA fed to sows had no impact on piglet weights or ADG (P>0.82). In the nursey period, overall gain (0.112±0.02 kg) was low in the first two weeks possibly due to health challenges. Supplementation of MCFA to sows or nursery pigs had no impact on body weights during the nursery period (P>0.32); however, absolute differences between groups increased with week [wean, 0.10kg; wk 2, 0.14kg; wk 4, 0.71kg; wk 6, 0.83kg) to the advantage of MCFA fed pigs. Pigs from MCFA fed sows had greater feed intake (P< 0.02) from 14 to 28-d and decreased gain:feed (P < 0.04) from 28 to 42-d compared to pigs from UNSUP sows. Overall, sow and nurser-y pigs fed MCFA had numerically greater 42-d BW, ADG, and ADFI. In conclusion, despite health challenges, supplementation with MCFA in gestation, lactation or in the nursery period improved piglet performance.


2016 ◽  
Vol 8 (8) ◽  
pp. 182
Author(s):  
Kanwar Priyanaka ◽  
Y. C. Gupta ◽  
S. R. Dhiman ◽  
R. K. Dogra ◽  
Sharma Madhu ◽  
...  

<p>The studies on heterosis were carried with four male sterile lines namely; ms<sub>7</sub>, ms<sub>8</sub>, ms<sub>9,</sub> ms<sub>10</sub> and 18 diverse pollinators as tester by using line × tester crossing programme. The 72 F<sub>1</sub> hybrids were produced and evaluated along with 22 parental lines during summer 2009 and rainy season 2009 in Randomized Block Design. Observations were recorded on nine quantitative traits during both the seasons. Highly significant variances for all the traits indicated the sufficient variability in the parental material for all the characters under study. The performance of F<sub>1</sub> hybrids was much better than the mean performance of parents during both the crop seasons. Appreciable heterosis was observed in all the characters, except flower weight in summer and plant height in rainy season.</p>


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