Pair Of Recessive Genes Research Articles

A recessive LRR-RLK gene causes hybrid breakdown in cotton.

An LRR-RLK gene causing interspecific hybrid breakdown between Gossypium. anomalum and G. hirsutum was identified by deploying a map-based cloning strategy. The self-destructing symptoms of hybrid incompatibility in most cases are attributed to autoimmunity. The cloning of genes responsible for hybrid incompatibility in cotton is helpful to clarify the mechanisms underlying hybrid incompatibility and can break the barriers in distant hybridization. In this study, a temperature-dependent lethality was identified in CSSL11-9 (chromosome segment substitution line) with Gossypium anomalum chromosome segment on chromosome A11. Transcriptome analysis showed the differentially expressed genes related to autoimmune responses were highly enriched, suggesting that expression of CSSL11-9 plant lethal gene activated autoimmunity in the absence of any pathogen or external stimulus, inducing programmed cell death (PCD) and causing a lethal phenotype. The lethal phenotype was controlled by a pair of recessive genes and then fine mapped between JAAS3191-JAAS3050 interval, which covered 63.87 kb in G. hirsutum genome and 98.66 kb in G. anomalum. We demonstrated that an LRR-RLK gene designated as hybrid breakdown 1 (GoanoHBD1) was the causal gene underlying this locus for interspecific hybrid incompatibility between G. anomalum and G. hirsutum. Silencing this LRR-RLK gene could restore CSSL11-9 plants from a lethal to a normal phenotype. Our findings provide new insights into reproductive isolation and may benefit cotton breeding.

Marker-Assisted Pyramiding of Genes for Multilocular Ovaries, Self-Compatibility, and Clubroot Resistance in Chinese Cabbage (Brassica rapa L. ssp. pekinensis)

Molecular marker-assisted gene pyramiding combined with backcrossing has been widely applied for crop variety improvement. Molecular marker identification could be used in the early stage of breeding to achieve the rapid and effective pyramiding of multiple genes. To create high-quality germplasm for Chinese cabbage breeding, multi-gene pyramiding for self-compatibility, multilocular, and clubroot resistance was performed through molecular marker-assisted selection. The results showed that self-compatibility and multilocular traits were controlled by a pair of recessive genes. Two flanking markers, sau_um190 and cun_246a, and marker Teo-1, based on the gene sequence related to multilocular ovaries, were used for multilocular ovary trait selection. Two flanking markers, SCF-6 and SC-12, and marker Sal-SLGI /PK1+PK4, based on the gene sequence, were used for self-compatibility selection. Two flanking markers, TCR74 and TCR79, closely linked to clubroot resistance gene CRb, were used as foreground selection markers. Based on Chinese cabbage genomic information, 111 SSR markers covering 10 chromosomes were applied for background selection. After multiple generations of selection, a multi-gene pyramided line from a BC4F2 population with self-compatibility, multilocular ovaries, and clubroot resistance was obtained with a high genomic background recovery rate. The improved pyramided line is expected to be utilized as a potential material in further breeding programs.

ハイドランジア装飾花の八重咲きの遺伝様式

Species belonging to the Hydrangea genus, including Hydrangea macrophylla (Thunb.) Ser. and H. serrata (Thunb.) Ser., have inflorescences consisting of decorative and non-decorative flowers. The generation of double-flowered decorative flowers is an important objective for hydrangea breeders. This study aimed to elucidate the inheritance pattern of double flowers in H. macrophylla and H. serrata. Double-flowered progeny were obtained from three out of eleven crosses between double-flowered cultivars as the seed parent and single-flowered cultivars or lines as the pollen parent. When double-flowered progeny were produced using three cross combinations, the progenitor of both double-flowered cultivars and single-flowered lines was the double-flowered cultivar ‘Jogasaki’. In progeny obtained from these crosses, the segregation ratio of double- and single-flowered types was 1:1. Conversely, all progeny obtained from a cross in which the double-flowered cultivar as the seed parent differed from the seed parent of the single-flowered line as the pollen parent bore single flowers, and double-flowered progeny were not produced. Double-flowered progeny were obtained in two out of four crosses among the single-flowered lines; the segregation ratio of double- and single-flowered types was 1:3. The single-flowered lines shared the same seed parents, ‘Jogasaki’ or ‘Sumidanohanabi’. These results indicate that the double-flowered phenotype of decorative hydrangea flowers may be a recessive characteristic controlled by a single major gene. In addition, these results indicate that double-flowered progeny can be obtained when a pair of recessive genes are identical.

Inheritance of late flowering in natural variants of soybean cultivars under short-day conditions

The objective of this work was to determine the inheritance of the long juvenile period trait in natural variants of the Doko, BR 9 (Savana), Davis, Embrapa 1 (IAS 5RC), and BR 16 soybean cultivars. Complete diallel crosses were made between the Doko and BR 16 cultivars and their variants. A 3:1 segregation ratio was observed in the F2 populations of the 'Doko' x Doko-18T, 'Doko' x Doko-Milionária, 'Davis' x São Carlos, and 'BR 9 (Savana)' x MABR92-836 (Savanão) crosses, indicating that the long juvenile period trait is controlled by a pair of recessive genes. The difference in late flowering between the Doko cultivar and both of its variants was caused by a recessive spontaneous mutation at the same genetic locus. However, the variants Doko-18T and Doko-Milionária are identical mutants that share a pair of genes that control the long juvenile period under short-day conditions. These mutants can be used in breeding programs to develop cultivars adapted to low-latitude tropical regions.

The inheritance of two novel subgynoecious genes in cucumber ( Cucumis sativus L.)

Cucumber ( Cucumis sativus L.), which is a vegetable crop, has served as the model system for sex expression in flowering plants, and the inheritance of sex expression in cucumber is well documented. However, the genetics of subgynoecism expression in cucumber had rarely been described. In this study, we investigated the inheritance of subgynoecious traits in cucumber plants with the inbred cucumber lines of subgynoecious ( C. sativus L. var sativus cv 97-17 and S-2-98) as the materials. Genetic analysis had showed the two subgynoecious inbred lines were controlled by one pair of recessive gene and one pair of incompletely dominant gene, which were designated presently as mod-F2 and Mod-F1, respectively. Furthermore, the mod-F2 and Mod-F1 loci, which enhance the intensity of femaleness, also inherited independently with F and M genes.

INHERITANCE OF PUBESCENCE TYPES IN MELON (CUCUMIS MELO L.): HISPID, GLABROUS AND PUBERULENT

The stems, petioles, and major veins of leaves are covered with bulbous-based bristles (hispid stem and leaf) in normal melon plant. The stem and leaf glabrous is a mutant controlled by a pair of recessive genes (gl). An unusual stem and leaf mutant was described in melon, this mutant is characterized by stem, petioles, and major veins of leaves are puberulent. The objective of these experiments was to study the genetic relationship of three pubescence traits. Two crossed were used to study the inheritance of pubescence type P A (M453, hispid) × P B (M455, puberulent), P B (M455, puberulent) × P c (M292, glabrous); and two sets of six generations (P A , P B , F 1 , F 2 , BC 1A , BC 1B and P B , P C , F 1 ', F 2 ', BC 1B ', BC 1C ') were developed. Based on performance of the 1st set of six generations, In the F 1 and BC 1A generation, all plants was normal (hispid) stem, the F 2 and BC 1B individuals segregated at the ratio showed the data were consistent with a 3:1 and 1:1 expected ratio respectively. It was confirmed that the puberulent type was inherited as a single recessive gene. The phenotype in another six generations of the cross P B ×P c showed F 1 'plant were normal (hispid), the ratio of BC 1B ' and BC 1C ' individuals segregated normal: puberulent and normal: glabrous were 1:1. The F 2 ' individuals showed three phenotype: normal, puberulent, glabrous, and the data of F 2 ' individuals segregated confirmed a good fit of 9 (normal): 3 (puberulent): 4 (glabrous) ratio, It shows that puberulent was non-allelic to glabrous, and that glabrous is recessive epistatic to puberulent. As a puberulant mutation, it is potentially useful in seeds production, genetic, and biochemical studies.

EST-SSR MARKER LINKED TO CUCUMBER TARGET LEAF SPOT RESISTANCE-RELATED GENE

Cucumber target leaf spot (Corynespora cassiicola (Berk. & Curt.) Wei.), a world wide fungicidal disease of cucumber, was first reported in Europe in 1906. It becomes a serious problem in cucumber protected cultivation in northern part of China recent years. A 241 F 2 population derived from F 1 of Q5 (resistant female) and P57-1 (susceptible male) was used as materials, their resistances to Corynespora cassiicola of cucumber were identified through seedling inoculation. The results indicated that the resistance to Corynespora cassiicola was controlled by a pair of recessive gene, and the susceptible was in the mode of incomplete dominant inheritance. The polymorphism between resistant and susceptible bulk of cucumber target leaf spot were studied using BSA method and SSR, EST-SSR, ISSR techniques. One hundred twelve SSR, 29 EST-SSR and 100 ISSR markers were screened, and a co-dominant EST-SSR marker was obtained. The resistant and susceptible F 2 plants possessed the 203 bp and the 207 bp fragments, respectively, and the mid-plants possessed both two fragments. The EST-SSR marker was closely linked to the cucumber target leaf spot resistance-related gene, and the genetic distance between the marker and the gene was 2.9 cM. The difference of the two fragments lied in the insert or deletion of 4 bases. Resistance of 47 inbred lines through seedling inoculation were compared with their results of marker detection, the coincidence rate was 91.5%.

The Evaluation and Utilization of New Genes for Brown Planthopper Resistance in Common Wild Rice (<i>Oryza rufipogon</i> Griff.)

Brown planthopper (BPH, Nilaparvata lugens Stal) is one of the most serious rice insect pests in Chinaand the world. Exploiting new resistance genes and breeding advanced genetic stocks are important for breeding resistance varieties. In this study, more than 1 200 accessions of common wild rice ( Oryza rufipogon Griff.), were evaluated for the resistance to several biotypes of BPH. 30 resistant accessions were obtained and 6 of them showed broad spectrum resistance to 5 or all of the 6 BPH biotypes, i.e. biotypes 1 and 2, Bangladesh, Mekong (Vietnam), Cuulong (Vietnam) and Pantnagar (India), which are spreading most rice growing regions in the world. Genetic analysis was turned out that the BPH resistance in these stocks was controlled by two pairs of recessive genes with duplicate interaction against biotypes 2 and Cuulong, but the resistance to the biotype Pantnagar was controlled by one pair of recessive gene. This indicated different genetic mechanism of reaction against BPH biotypesin the resistant sources. The two recessive genes existing in the entry 2183 might be new discovered genes as no BPH resistance gene has been reported in these chromosome regions. They were tentatively designated asbph18 (t) and bph19 (t), respectively. A total of 143 entries of advanced genetic stocks resistant to BPH and 6promising resistance lines or hybrid combinations with high yield or good quality were bred. These resistant advanced genetic stocks set a solid foundation for breeding new resistance varieties.

Isolation and characterization of a sterile-dwarf mutant in Asian cotton (Gossypium arboreum L.)

Plant height is an important trait in cotton. To elucidate the molecular mechanisms of the dwarf phenotype, a sterile-dwarf mutant derived from Gossypium arboreum L. cv. Jinhuazhongmian was developed by (60)Co gamma-ray irradiation. The results demonstrated that the sterile dwarf mutant phenotype was controlled by a pair of recessive gene, which was designated sd(a). Plants carrying the sd(a) gene contained lower levels of indole-3-acetic acid (IAA) and abscisic acid (ABA) compared with wild-type (WT) plants. The chlorophyll content and net photosynthetic rate in mutant leaves were markedly decreased. However, it was possible that ABA biosynthesis or signaling was involved in governing the sd(a) phenotype. Semi-quantitative RT-PCR analysis detected 13 differentially expressed ESTs, and the sterile-dwarf mutant exhibited decreased expression levels relative to the WT. The role of nine potential hormone biosynthetic genes in the synthesis of IAA, ABA, polyamines (PAs) and jasmonic acid (JA) were discussed.

Sequential hygienic behavior in Carniolan honey bees (Apis mellifera carnica)

We examined the sequence, order or steps of hygienic behavior (HB) from pin-killed pupae until the removal of them by the bees. We conducted our study with four colonies of Apis mellifera carnica in Germany and made four repetitions. The pin-killing method was used for evaluation of the HB of bees. The data were collected every 2 h after perforation, totaling 13 observations. Additionally, for one hygienic colony and another non-hygienic colony, individual analyses of each dead pupa were made at every observation, including all details, steps or sequences of HB. The bees recognize the cells containing dead pupae within 2 h after perforation, initially making a hole in the capping, which is the beginning of HB. Uncapping of the dead brood cell reached maximum values from 4 to 6 h after perforation; after 24 h, practically all cells were already uncapped. Another variable, called brood partially removed, was analyzed 4 h after perforation, after the cells had been perforated, which involved uncapping, followed by partial or total removal of the brood. Maximum values of brood partially removed were found 10 h after perforation, though such cells could be found up to 48 h after perforation. The most frequent sequence of events in both colonies was: capped cell --> punctured cell --> brood partially removed --> empty cell. A new model of three pairs of recessive genes (uncapping u1, u2 and remover r) was proposed in order to explain the genetic control of the HB in Apis mellifera. We recommend evaluating HB 24 h after perforation and using a correction factor to compensate for control removal levels. We found a series of details of HB, which allow a study of how various factors may affect the sequence of the activities involved in HB and investigation of the genetics that controls this process.

Inheritance of thermo-photoperiod sensitive male sterility in wheat

The fertility of a wheat male sterile line 337S was investigated in 4 consecutive years with 18 different sowing dates. Line 337S showed high sterility under both short daylength/low temperature and long daylength/high temperature during ear development. It has 2 time windows to be used as a male sterile line for hybrid seed production. Its fertility rate can be >50% with suitable sowing time; thus, it can be self-maintained as a male sterile line. Line 337S was reciprocally crossed with 7 common wheat varieties and the fertility of their F1, F2, and BC1 hybrids was investigated at different sowing dates. The results showed that recessive nuclear genes controlled male sterility in 337S and no cytoplasmic effect was observed. All common wheat varieties were able to restore its fertility. The male sterility was controlled by a pair of recessive genes under short daylength/low temperature, but was governed by 2 pairs of recessive genes under long daylength/high temperature. This novel male sterile line provides a new tool for using heterosis in wheat.

Monosomic analysis of Helminthosporium leaf blight resistance genes in wheat

AbstractA set of 21 monosomic (2n ‐ 1) and the disomic (2n) lines of the ‘Chinese Spring’ cultivar were crossed with ‘Chirya‐3′, the CIMMYT synthetic wheat line which has been identified as highly resistant for Helminthosporium leaf blight disease (HLB), in order to locate the genes governing disease resistance. The F1 and segregating populations were challenged and screened against the most virulent pure mono‐conidial HLB isolate KL‐8 (Karnal, India). The F1 progenies of the crosses were found to be susceptible because of the recessive nature of resistance. The F2 progeny of the control cross (‘Chinese Spring’בChirya‐3’), segregated in the ratio of 1: 15 (resistant: susceptible), indicating that resistance to HLB was controlled by a pair of recessive genes. While the F2 progeny of 19 monosomic crosses segregated in the ratio of 1: 15 (resistant: susceptible), the progeny of the remaining two crosses, 7B and 7D, deviated significantly from the ratio, revealing that 7B and 7D were the critical chromosomes for resistance genes that were located one on each chromosome. Moreover, the critical lines, 7B and 7D, confirmed the digenic complementary recessive nature of gene action by fitting well with the overall pooled F2 segregation ratio of 13: 51 (resistant: susceptible) as expected for digenic complementary recessive resistance. The F3 segregation ratios of the critical crosses, based on their pooled F2 analysis, was estimated as 19: 32: 13 (non‐segregating susceptible: segregating as susceptible and resistant: non‐segregating resistant). F3 progenies when tested with these ratios showed goodness‐of‐fit, confirming that the two pairs of recessive resistance genes were located on chromosomes 7B and 7D.

Research on the ultrafast fluorescence property of thylakoid membranes of the wild-type and mutant rice

A high yielding rice variety mutant (Oryza sativa L., Zhenhui 249) with low chlorophyll b (Chl b) has been discovered in natural fields. It has a quality character controlled by a pair of recessive genes (nuclear gene). The partial loss of Chl b in content affects the efficiency of light harvest in a light harvest complex (LHC), thus producing the difference of the exciting energy transfer and the efficiency of photochemistry conversion between the mutant and wild-type rice in photosynthetic unit. The efficiency of utilizing light energy is higher in the mutant than that in the wild-type rice relatively. For further discussion of the above-mentioned difference and learning about the mechanism of the increase in the photochemical efficiency of the mutant, the pico-second resolution fluorescence spectrum measurement with delay-frame-scanning single photon counting technique is adopted. Thylakoid membranes of the mutant and the wild-type rice are excited by an Ar+ laser with a pulse width of 120 ps, repetition rate of 4 MHz and wavelength of 514 nm. Compared with the time and spectrum property of exciting fluorescence, conclusions of those ultrafast dynamic experiments are: 1) The speeds of the exciting energy transferred in photo-system I are faster than that in photo-system II in both samples. 2) The speeds of the exciting energy transfer of mutant sample are faster than those of the wild-type. This might be one of the major reasons why the efficiency of photosynthesis is higher in mutant than that in the wild-type rice.

English

  The inheritance of resistance to head bug (Eurystylus oldi) was studied in ten populations of sorghum derived from crossing three susceptible sorghum elite varieties (ICSV 111, ICSV 112 and ICSV 400), and two resistant sorghum varieties (Malisor 84-7 and KSV 4). Parental lines, F1 and F2 populations were sown on a Randomized Complete Block Design in two replications. Artificial infestation of head bugs on sorghum was employed in carrying out the experiment. Samples of 5 panicles each from every artificially infested plot were observed. Resistance to head bug in sorghum seems to be controlled by a single pair of recessive genes in Malisor 84-7 x ICSV 400 and Malisor 84-7 x ICSV 111. The cross, KSV 4 x ICSV 112 appeared to be controlled by double recessive pair of genes. Head bug population affects quality of grains rather than the yield produced. There is a negative correlation (-0.095) between head bug population and the germination percentage of the grain. Positive relationship exists between glume size and head bug population, which suggests that longer glumes harbour more head bug.   Key words: Head bug (Eurystylus oldi), Infestation, Anthesis, Resistance, Susceptible, Inheritance.  

Inheritance of agronomic traits from the Chinese barley dwarfing gene donors 'Xiaoshan Lixiahuang' and 'Cangzhou Luodama'

The inheritance of agronomic traits from the barley dwarfing gene donors ‘Xiaoshan Lixiahuang’ and ‘Cangzhou Luodamai’ was studied. The results indicated that dwarf plants, six-row and short spikes, dense spikelets and naked kernels, respectively, were controlled by one pair of recessive genes, but a toothed awn was determined by one pair of dominant genes in both barley cultivars. The genes for the six characters in ‘Xiaoshan Lixiahuang’ were allelic to those in ‘Cangzhou Luodamai’. Genetic linkage was found among the genes for plant height, spike length and spikelet density. They were located on the long arm of chromosome 3 (3HL) in the order: plant height, spikelet density, spike length. The genes for naked kernels, six-row spikes and tooth awns were independent of each other, and carried on the long arms of chromosomes 1(7H), 2(H) and 7(5H), respectively. The dwarfing genes were the same as the gene uz in Japanese and Korean barley cultivars.

A chlorophyll‐reduced seedling mutant in oilseed rape, Brassica napus, for utilization in F1 hybrid production

AbstractA mutant chlorophyll‐reduced (Cr) seedling with yellow‐green cotyledons and leaves was obtained from the Brassica napus inbred line 3529 induced by fast neutron and diethyl sulphate (DES). Genetic analysis revealed that the Cr seedling marker trait was controlled by a pair of recessive genes. A randomized complete block design was used to evaluate its agronomic performance. Results from 2 years of tests indicated that the seed yield of Cr lines was significantly lower than that of normal green plants; however, when the Cr gene was in the heterozygous condition, no deleterious effects on yield characteristics and disease resistance were observed. The Cr seedling marker trait was introduced into male‐sterile lines, and Cr male‐sterile lines revealed the same superior combining ability as normal chlorophyll (Nc) lines. The Cr trait can therefore be used as a marker to produce hybrid seed.

Inheritance of the Trait of Male Sterility in Cryptomeria japonica

Matings of male-sterile C. japonica and fertile elite C. japonica, as well as backcross seedlings of male-sterile trees, were carried out to clarify the genetic trait of male sterility of the C. japonica. The seeds from male-sterile C. japonica were germinated in an incubator and grown them in the greenhouse between 1994 and 1997. The seedlings were treated with 100 ppm gibberellin at early July 1994 and early July 1995 to promote the formation of male flowers. In the middle of January 1995, the male flowers of all seedlings were examined under the microscope to confirm the production of pollen. In January 1996, pollen did not developed in to the male flowers from the seedlings between the fertiled elite and backcross C. japonica. In January 1997, all seedlings of elite C. japonica produced pollen in their male flowers; however, pollen did not developed in 55 out of 120 backcrossed seedlings. This evidence suggests that the heredity pattern of male sterility in C. japonica is nuclear male sterility controlled by a pair of recessive genes.

Geographical distribution of genes causing hybrid breakdown in varietal crosses of Asian cultivated rice

In a backcrossing program to introduce the wx (glutinous endosperm) gene from a Thai upland rice cultivar, Col.No.15, to a Japanese cultivar, Sasanishiki, of Asian cultivated rice, Oryza sativa L., weak plants were observed in the BC1F1 generation. These weak plants were characterized by poor growth and discoloration at the tillering stage, though they were completely fertile. Hybrid breakdown, which is defined as hybrid weakness and sterility detected in the F2 and later inbred generations of varietal crosses, is controlled by a pair of recessive genes, hwd1 and hwd2, at unlinked loci. Two dominant genes at either the same or different loci, Hwd1/Hwd1 hwd2/hwd2, hwd1/hwd1 Hwd2/Hwd2 or Hwd1/hwd1 Hwd2/hwd2, are needed for normal growth. Using tester lines homozygous for a pair of recessive genes selected in the BC1F3 generation, the genotypes for hybrid breakdown of 100 Asian rice cultivars were determined based on the phenotype of F1 plants. Clinal variation for hybrid breakdown was observed. Cultivars with two dominant alleles at either hwd1 or hwd2 locus, were mainly found in insular Asia (Japan, Philippines and Indonesia), while the frequency of cultivars with four dominant alleles was more common in cultivars from continental Asia. Roles of hybrid breakdown in genetic differentiation of Asian cultivated rice are discussed.

トマト‘ファースト’種子へのガンマー線照射によって誘発された突然変異のスペクトラム とくに葉緑素部分欠損形質について

トマト固定品種'ファースト'の乾燥種子に総線量100, 200および400Gyのガンマー線(60Co)を照射して突然変異の誘発を試みた.照射時間はいずれも5時間とした.1. 照射種子(M1)はいずれも発芽するが, 線量が高くなるほど実生の生育が劣り400Gy区では子葉展開後に枯死した.100Gy区では照射種子の約80%, 200Gy区では38%の株でM2種子が採種できた.M1株の花粉稔性は照射区で劣り, 100Gy区より200Gy区で顕著であったが, 全不稔の花は存在しなかった.また, 花粉稔性と種子数の間には相関は見られなかった.2. M2世代において, 100Gy区の188系統では3種類の突然変異が出現した.つまり, 葉幅の狭い系統, 10%以下の可稔花粉系統, オリジナルと同じ雄ずい型の雄性不稔系統である.200Gy区の88系統では9種類の突然変異が出現した.つまり, 葉緑素突然変異としてアルビノ, ビリデイス, キサンタおよび部分欠損の4系統, 10%以下の可稔花粉系統, オリジナルと同じ雄ずい型の雄性不稔系統, 葯が萎縮して褐色となり柱頭が突出する雄性不1稔系統, 葯は正常に発育するが, その葯の先端に柱頭が突出する雄性不稔系統および発芽不能系統であった.以上の結果より, トマト種子から突然変異を誘発する場合のガンマー線の好適照射線量は200Gy付近にあると考えられた.3. 葉緑素部分欠損形質は, ヘテロ自家受粉種子における分離比が正常 : 欠損=3 : 1に適合したことから, 1劣性遺伝子によって支配されているものと推察された.葉緑素欠損葉において生育中に線状や点状に緑色を発現する個体があり, その発現部分が拡大すると個体の生存は可能となった.

Genetic analysis of the complete maintainer for genetic-male-sterility in upland cotton

The inheritance of the complete maintainer for Dong A-type genetic-male-sterility (GMS) in cotton was controlled by one pair of recessive major genes for male-sterility and polygenic system for pollen-spreading character together. When a dominant major gene for fertility was present, the action of the polygenic system was concealed and GMS was inherited as a qualitative character conditioned by one pair of recessive genes. But when the major genes were homozygous recessive, the polygenic system manifested modificatory effects on GMS, making GMS plants spread some pollen or partially fertile Among the genie effects of polygenic system on pollen-spreading character, additive [d], dominance [h] and additive ×dominance epistasis [j] were all very significant, [d] and [j] were positive and [h] was negative. This type of genetic model is referred to as Major Gene-Polygene Interaction Model in Crops.