Crop Science
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF) Free
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (1)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Jan, C.C.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Jan, C.C.
Agricola
Right arrow Articles by Jan, C.C.
Crop Science 40:1535-1538 (2000)
© 2000 Crop Science Society of America

CROP BREEDING, GENETICS & CYTOLOGY

Cytoplasmic Male Sterility in Two Wild Helianthus annuus L. Accessions and Their Fertility Restoration

C.C. Jan

USDA-ARS, Northern Crop Science Laboratory, PO Box 5677, Fargo, ND 58105 USA

janc{at}fargo.ars.usda.gov


   ABSTRACT
TOP
 ABSTRACT
INTRODUCTION
 Materials and methods
 Results and discussion
 REFERENCES
 
Commercial sunflower hybrids have been produced by means of a single male-sterile Helianthus petiolaris Nutt. cytoplasm and a few fertility restoration genes. The objectives of this study were to characterize cytoplasmic male-sterility (cms) systems in wild H. annuus L. accessions (PI 413178 and PI 413180) and to determine the inheritance of fertility restoration. Male-sterile plants were identified and maintained by backcrossing with inbred line HA89. Male-fertile progenies from crosses between cms plants of the two PIs and USDA inbred lines indicated the presence of fertility restoration genes in P21, RMAX1, and PI 413178 for cms PI 413178 (cms-ANN2), and P21, RHA280, RHA801, RPET2, and PI 413180 for cms PI 413180 (cms-ANN3). All heterozygous male-fertile plants of backcross progenies, except for RHA280, crossed to cms plants resulted in a segregation ratio of one male-fertile to one male sterile, indicating a single dominant gene controlling fertility restoration. The backcross progeny of cms PI 413180/HA89//cms PI 413180/RHA280 had a segregation ratio of one male-fertile to three male sterile, suggesting two complementary dominant genes for fertility restoration. Pollinating male-fertile plants of both accessions with HA89 pollen resulted in male-fertile and male-sterile F1 plants, suggesting the existence of male-sterile cytoplasm and heterozygosity for restoration genes in the male-fertile plants. In field tests, male-sterile PI 413178/4*HA89 and PI 413180/4*HA89 plants produced no seed after self-pollination, and 95 and 98% seed set, respectively, under open-pollination indicating complete male-sterility and female fertility. The new cms sources from wild H. annuus and corresponding fertility restoration genes provide diversity for sunflower hybrid production.


   INTRODUCTION
TOP
 ABSTRACT
 INTRODUCTION
Materials and methods
 Results and discussion
 REFERENCES
 
A MALE-STERILE CYTOPLASM derived from Helianthus petiolaris subsp. petiolaris (PET1) and the subsequent identification of dominant fertility restoration genes led to the development and commercialization of sunflower hybrids (Leclercq, 1969; Enns et al., 1970; Kinman, 1970; Vranceanu and Stoenescu, 1970). This source of cms and a few fertility restoration genes, including the widely used Rf1 and Rf2 genes, have been used almost exclusively for sunflower hybrid production worldwide (Miller and Fick, 1997). New cms sources and fertility restoration genes are needed to increase the genetic diversity of the commercial hybrids.

Over 60 additional sources of cms have been identified from progenies of crosses between wild Helianthus species and cultivated lines (Leclercq, 1983; Whelan and Dedio, 1980; Anashchenko et al., 1974; Serieys, 1991, 1994; Heiser, 1982; Vranceanu et al., 1986; Vulpe, 1972; Christov, 1994), from wild species (Heiser, 1982; Serieys, 1984; Skoric et al., 1987; Jan, 1990; Jan and Zhang, 1994), or from induced mutation (Jan and Rutger, 1988). Fertility restoration genes have been identified in 30 sources, with detailed inheritance studies completed for 17 (Serieys, 1999).

Male-sterile plants were observed in two H. annuus accessions in a disease infected nursery near Moorhead, MN. Preliminary studies of these two male-sterile sources and the corresponding fertility restoration genes suggested that these accessions were potentially useful cms sources (Jan, 1990). The objectives of this study were to characterize the cms sources, and to determine the inheritance of pollen fertility restoration.


   Materials and methods
TOP
 ABSTRACT
 INTRODUCTION
 Materials and methods
Results and discussion
 REFERENCES
 
A wild Helianthus nursery was established near Moorhead, MN, for Sclerotinia wilt [Sclerotinia sclerotiorum (Lib.) De Barry] resistance evaluations in the summer of 1987. The 128 entries tested included 124 accessions of wild H. annuus, two of H. petiolaris, and one each of H. nuttallii T. & G. and H. pauciflorus Nutt. (=rigidus). About 60 plants per entry were established. Typical male-sterile plants, without extruding anthers or pollen production, were observed in two accessions of H. annuus, PI 413178 and PI 413180.

Twelve USDA inbred lines and bulk pollen from male-fertile plants of each of the two H. annuus accessions were used to pollinate the male-sterile plants of PI 413178 and PI 413180. Additional crosses between wild male-sterile plants or male-sterile F1 plants and HA89 as the recurrent pollen parent were made in the greenhouse. The F1 and BC1F1 plants grown in the field were scored visually for male fertility. The male-fertile plants had normal anther dehiscence and pollen production and the male-sterile plants showed neither anther extrusion nor pollen production.

Since self-incompatibility in male-fertile F1 segregants prevented the production of F2 populations, the male-fertile F1s were used as the pollen parent in testcrosses to male-sterile plants. The sterile progenies were maintained by backcrossing cms plants with the line HA89. Testcross progenies were scored visually for segregation of male-fertile and male-sterile plants in the field in 1989 and in the greenhouse in 1990 and 1991. The testcross segregation ratios were compared with the theoretical ratio for a 1-gene model by Chi-square analyses. All male-fertile testcross progenies in the 1991 greenhouse planting were evaluated for pollen stainability (Alexander, 1969). Male-sterile plants from the crosses PI 413178/4*HA89 and PI 413180/4*HA89 were grown in the field in 1990. Randomly selected heads were either self-pollinated or open-pollinated. Seed set provided estimates of male and female fertility. The seed set was considered the number of filled seeds divided by the number of florets in each head, expressed as a percentage.

Original seed of PI 413178 and PI 413180 were grown in the greenhouse in 1989 to estimate the frequency of male-sterile plants. Eleven and eight male-fertile plants of PI 413178 and PI 413180, respectively, were emasculated and pollinated with pollen from the line HA89. Fifteen progeny plants for each of the 19 F1 families were grown in the field in 1991 to examine the possible existence of male-fertile cytoplasms in those 19 male-fertile plants.

Working with lines derived from the same two H. annuus accessions, Serieys (1991)(personal communication) pollinated cms plants with 18 fertility restoration testers, including 16 USDA lines and two French lines, and observed only male-sterile plants in the F1 progenies. He designated the cms cytoplasm derived from PI 413178 as cms-ANN2 and the cms cytoplasm from PI 413180 as cms-ANN3 (Serieys, 1991). The cms sources described in this report were discovered independently and without knowledge of the cms lines identified by Serieys.


   Results and discussion
TOP
 ABSTRACT
 INTRODUCTION
 Materials and methods
 Results and discussion
REFERENCES
 
Greenhouse grown plants of the PI 413178 and PI 413180 accessions produced a high frequency of male-sterile progenies: 12 male-fertile and six male-sterile plants (PI 413178), and 12 male-fertile and nine male-sterile plants (PI 413180). Complete male sterility was observed in progenies after backcrossing non-restoring recurrent parents to both accessions, indicating the cytoplasmic control of male sterility. A low frequency of dominant nuclear fertility restoration genes was identified in some USDA inbred lines involved in the crosses (Table 1) . P21 and RMAX1 contained fertility restoration genes for cms PI 413178, and P21, RHA280, RHA801, and RPET2 provided fertility restoration genes for cms PI 413180. When a fertility restoration gene exists at a low frequency in a line, pollination with bulk pollen of many plants of the respective line onto the cms sources, and large F1 populations increase the probability of its identification.


View this table:
[in this window]
[in a new window]
  		Table 1 Frequency of F1 male-fertile (MF) and male-sterile (MS) H. annuus plants after crossing MS plants of PI 413178 (cms-ANN2) and PI 413180 (cms-ANN3) with 12 sunflower restoration testers, and male-fertile plants of PI 413178 and PI 413180

 
The suspected rarity of fertility restoration genes in cultivated lines for cms-ANN2 and cms-ANN3 is evident. Not surprisingly, male-fertile plants of PI 413178 and PI 413180 had the highest frequency of restoration genes from their respective cms sources (Table 1). Seven USDA restoration lines for the cms-PET1 cytoplasm were unable to restore the cms-ANN2 and cms-ANN3 cytoplasms. These two cms sources had different reactions to the restoration testers indicating distinct mechanisms of cytoplasmic male sterility.

A recent study of cms plants in four wild H. annuus accessions, PI 406647, PI 413024, PI 413043, and PI 413158, confirmed the high frequency of fertility restoration genes in each accession (Jan, 1990). In another study, plants with reduced vigor occurred in backcross progenies when substituting the nucleus of the line HA89 into the cytoplasms of perennial diploid Helianthus species (Jan, 1992). Genes compensating for the cytoplasmic deficiency were recovered from normal segregants and those genes originated from the respective wild species.

Deriving nuclear fertility restoration gene(s) from a wild Helianthus species cms donor provides an alternative when restoration genes are not found or are very rare in cultivated genotypes. Backcrossing male-sterile segregants with sterility maintainer lines has as a result total male-sterile progenies. Backcrossing maintainer lines onto male-fertile segregants is a way of developing restoration lines. After sufficient backcrosses, isogenic lines differing only in the presence or absence of restoration genes can be produced by self-pollination of the male-fertile segregants. Isogenic lines plus the maintainer line in the original H. annuus cytoplasm will provide material for testing the effects of the new cms cytoplasm as well as the new restoration gene(s).

With the exception of RHA280, in eight cases testcross progenies of male-fertile plants (heterozygous for fertility restoration and with sterile cytoplasms), had segregation ratios of one male-fertile to one male-sterile plant, indicating that a single dominant gene controlled fertility restoration (Table 2) . The segregation ratio of one male fertile to three male sterile in the testcross involving RHA280 indicated that this line possessed two dominant complementary genes responsible for fertility restoration of the male-sterile PI 413180 cytoplasm.


View this table:
[in this window]
[in a new window]
  		Table 2 Segregation of male-fertile (MF) and male-sterile (MS) H. annuus plants, and pollen stainability of testcross progenies of heterozygous MF plants crossed with MS plants in cms cytoplasms of PI 413178 and PI 413180, respectively

 
Low self-compatibility in the progeny makes pollen stainability a better indicator of fertility restoration than the seed set. The heterozygous male-fertile testcross progenies, for fertility restoration genes of P21, PI 413178, and RMAX1, restored pollen stainability to over 90%, indicating complete dominance. For cms PI 413180, restoration genes from PI 413180, P21, and RPET2 produced an average pollen stainability of 81, 72, and 81%, respectively, with a wide range of variation within each testcross combination. These results indicated partial dominance and the presence of modifier genes. Further selection for fertility restoration in these three sources is necessary before being used for commercial hybrid production. Testcross progenies involving RHA801 were not available for pollen evaluation. However, pollen stainability was evaluated in 29 male-fertile plants from a cross between cms PI 413180/3*HA89 and cms PI 413180/2*HA89//RHA801, F2, and an F2 plant homozygous for the RHA801 restoration gene. The observed 95% pollen stainability, with a range of 82 to 100%, indicated that the fertility restoration gene in RHA801 conferred nearly complete fertility with dominant gene action.

Since the male-fertile plants of these two accessions also provided fertility restoration genes, 11 and 8 male-fertile plants of PI 413178, and PI 413180, respectively, were pollinated with HA89 to determine if the male-fertile plants also possessed cms cytoplasms. All the F1 families segregated for male-sterile plants suggesting that all plants in both accessions have male-sterile cytoplasm. Fertility of those male-fertile plants is assumed to be the result of restoration genes. The number of fertility restoration genes in each accession and their allelic relationships have not been determined.

To be useful for hybrid seed production, a cms line needs complete male sterility and female fertility. In our 1990 field planting, cytoplasmic male-sterile plants of PI 413178/4*HA89 produced no seed in 11 heads after self-pollination, and an average of 95% seed set upon open-pollination. Similarly, cytoplasmic male-sterile plants of PI 413180/4*HA89 produced no self-pollinated seed set in 19 heads and an average of 98% seed set in eight open-pollinated heads. These results indicated that both cytoplasm sources had complete male sterility and completely female fertility. Presently, a cms cytoplasm of a related species, H. petiolaris, is used for commercial sunflower hybrid production. Adverse cytoplasmic-nuclear interactions are likely to occur between distantly related species. Cytoplasmic-nuclear interactions producing plants with reduced vigor were recorded when the nucleus of the line HA89 was incorporated in the cytoplasm of five diploid perennial Helianthus species (Jan, 1992). Since the two new cms sources are from H. annuus, the same species as cultivated sunflower, it is supposed it would be less likely to cause adverse cytoplasmic-nuclear interactions affecting commercial production.

This paper describes the isolation of cytoplasmic male sterility system from two wild H. annuus accessions, PI 413178 and PI 413180. Single dominant fertility restoration gene(s) were identified for both cms PI 413178 (cms-ANN2), and cms PI 413180 (cms-ANN3). Backcross progeny of cms PI 413178 and cms PI 413180 with HA89 had complete male sterility and female fertility. These represent the first two cms sources from wild H. annuus with restoration genes identified and genetically evaluated. They are different from other reported cms cytoplasms and, together with their restoration gene(s), will reduce the genetic vulnerability of sunflower hybrids by providing an alternative to the cms-PET1 cytoplasm.

Received for publication June 1, 1999.


   REFERENCES
TOP
 ABSTRACT
 INTRODUCTION
 Materials and methods
 Results and discussion
 REFERENCES
 




This article has been cited by other articles:


Home page
 Crop Sci.Home page
C.C. Jan
Registration of Two Cytoplasmic Male-Sterile and Eight Fertility Restoration Sunflower Genetic Stocks
Crop Sci., June 20, 2006; 46(4): 1835 - 1836.
[Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF) Free
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (1)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Jan, C.C.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Jan, C.C.
Agricola
Right arrow Articles by Jan, C.C.

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
The SCI Journals Agronomy Journal Vadose Zone Journal
Journal of Natural Resources
and Life Sciences Education		 Soil Science Society of America Journal
Journal of Plant Registrations Journal of
Environmental Quality		 The Plant Genome