Presently, selection of hybrid seedlings in coconut nurseries
relies on morphological markers, some of them being days taken for
germination, vigour of seedlings in terms of leaf production, higher
collar girth during a specific duration and petiole colour. The selection
of hybrids by petiole colour (Bourdeix, 1988) has limitations as
it is reliable only if progenitors homozygous for yellow, red or green
petiole are used. Furthermore, many of the varieties and hybrids are
phenotypically less distinct at early stages making morphological selection and evaluation more difficult. Identification of genuine
D
×
T (Dwarf
×
Tall) hybrids in the nursery stage is still more
difficult task if the female parent is a green dwarf in which case,
petiole colour is not useful for selection of hybrids. Though widely
adopted and practiced, purity assessments based on morphology is
often affected by environment, besides the higher requirement of
time and resources. Identification of molecular markers for distinguishing
plant-type character, therefore, is imperative for isolating
true-to-type high-yielding tall and hybrid lines in the early stage
of coconut breeding programmes which would be helpful in the
commercial hybrid seedling production activities in coconut. Differentiation
of dwarf, tall and hybrid types in the nursery based
on combined application of morphological and molecular markers would be expected to ensure quality of planting material in terms
of genetic purity.
In this study, we have described a technique of DNA pooling and
RAPD technique to identify markers linked to tall-type palm trait
in coconut. The methodology of pooling DNA for isolation of traitspecific
markers has been reported earlier in Chinese jujube (Peng
et al., 2001), Ponkan mandarin (JinPing et al., 2009) and betel vine
(Khadke et al., 2012) and this methodology proved to be effective
and practical in coconut too.
The fidelity of RAPD as a genetic marker technique has been
questioned because of the numerous technical disadvantages associated
with the RAPD technique. The reproducibility of RAPD is
affected by many factors: the quality of template DNA, the concentration
of primer and template, the different sources of DNA
polymerase, etc. The reproducibility and reliability of RAPD assays
can be significantly improved by the conversion of RAPD to SCAR
markers, by developing longer, and hence, more specific primers
from RAPD sequences. The linkage of the SCAR marker to talltype
palm trait in coconut was validated by screening the designed
primer pair in a range of tall and dwarf coconut accessions of different
geographical origins indicating the usefulness of the SCAR
makers for marker-assisted breeding.
In earlier studies, RAPD markers have been utilized for genetic
diversity studies of coconut accessions (Ashburner et al., 1997;
Upadhyay et al., 2004), but there are no reports of tagging of planttype
trait in coconut using molecular marker technology as in other
plant species such as Brassica rapa (Muangprom and Osborn, 2008),
Brassica napus (Foisset et al., 1995), Prunus (Manago and Bliss,
1998), wheat (Sourdille et al., 1998) and banana (Damasco et al.,
1996).
In conclusion, a marker related to tall-type plant trait has been
identified using RAPD markers. The SCAR primers designed using
this sequence variation was found to be specific for tall accessions
making the technique more stringent and specific when compared
with the RAPD marker. Studies of inheritance of plant-type character
in coconut has occupied a major place in coconut breeding
programmes as most of these programmes aim in developing a
D
×
T or T
×
D hybrids. The SCAR marker can be utilized to distinguish
selfed progenies in D × T crosses, as presented in this study.
Also, during selection of pure dwarf progenies in nurseries, the
SCAR marker would be of immense use in culling out of out-crossed
seedling progenies resultant of tall pollen contamination. Thus,
the SCAR marker for distinguishing tall and dwarf coconut accessions
would give headway in establishing further varietal identity,
achieving varietal purity within germplasm and ensuring the quality
of planting material in hybrid planting material production in
coconut.
ผลลัพธ์ (
จีนดั้งเดิม) 1:
[สำเนา]คัดลอก!
目前,選擇的雜交後代幼苗在椰子托兒所依靠形態學標記,其中一些被採取的天萌發,幼苗的葉的生產,更高的活力在一個特定的持續時間和葉柄顏色衣領周長。所選內容混合動力車的葉柄的顏色 (Bourdeix,1988年) 有作為的局限性它是可靠的只有當祖純合子為黃色、 紅色或綠色使用葉柄。此外,許多品種和混合動力車都是表型不明顯在早期階段使形態的選擇和評價更加困難。真正的鑒定D×T (小矮人×高) 雜交育苗階段仍然更重要的是艱巨的任務,如果母本是綠色的小矮人在這種情況下,葉柄顏色不是對於雜交種選育的有用的。雖然廣泛通過練習,基於形態學的純度評估並經常受到環境中,除了更高的要求時間和資源。鑒定的分子標記鑒別植物類型字元,因此,有必要為隔離true-型高產高和混合線在早期階段育種方案,這將有助於在椰子在椰子的商用混合苗生產活動。分化在托兒所裡的小矮人、 高和混合類型的基礎將預期形態學和分子標誌物的聯合應用,以確保在條件種植材料的品質遺傳純度。在此研究中,我們已經描述了一種 DNA 彙集法技術和RAPD 技術以識別標記連結到高型棕櫚特質在椰子。Traitspecific 分離池 DNA 的方法標記已早于棗 (彭等人,2001 年),柑 (金平等人,2009年) 和檳榔(Khadke 等人,2012年),這種方法被證明是有效和實用的椰子太。逼真度的 RAPD 作為一種遺傳標記技術已經質疑,因為相關聯的眾多技術缺點用 RAPD 技術。RAPD 的重現性是受許多因素的影響: 範本 DNA 濃度的品質底漆和範本不同的 DNA 來源聚合酶,等等。重現性和可靠性的 RAPD 分析可以通過 RAPD 轉為瘢痕明顯改善標記,通過開發更長時間,並因此更特異性引物從 RAPD 序列。SCAR 標記對 talltype 的聯繫椰子棕櫚性狀通過篩選不同的設計進行了驗證在一系列的高層和矮椰子加入的不同對引物該值指示疤痕的有用性的地理起源分子標記輔助育種的製造商。已在早些時候的研究中,用於 rapd 分子標記遺傳椰子加入 (Ashburner et al.,1997 年 ; 多樣性的研究阿帕德海耶等人,2004 年),但有沒有標注的株型的報導trait in coconut using molecular marker technology as in otherplant species such as Brassica rapa (Muangprom and Osborn, 2008),Brassica napus (Foisset et al., 1995), Prunus (Manago and Bliss,1998), wheat (Sourdille et al., 1998) and banana (Damasco et al.,1996).In conclusion, a marker related to tall-type plant trait has beenidentified using RAPD markers. The SCAR primers designed usingthis sequence variation was found to be specific for tall accessionsmaking the technique more stringent and specific when comparedwith the RAPD marker. Studies of inheritance of plant-type characterin coconut has occupied a major place in coconut breedingprogrammes as most of these programmes aim in developing aD×T or T×D hybrids. The SCAR marker can be utilized to distinguishselfed progenies in D × T crosses, as presented in this study.Also, during selection of pure dwarf progenies in nurseries, theSCAR marker would be of immense use in culling out of out-crossedseedling progenies resultant of tall pollen contamination. Thus,the SCAR marker for distinguishing tall and dwarf coconut accessionswould give headway in establishing further varietal identity,achieving varietal purity within germplasm and ensuring the qualityof planting material in hybrid planting material production incoconut.
การแปล กรุณารอสักครู่..

ผลลัพธ์ (
จีนดั้งเดิม) 3:
[สำเนา]คัดลอก!
目前,選擇在椰子樹苗的混合托兒所
依靠形態標記,其中一些被天採取
發芽、活力的樹苗的葉的生產、高
領周長在一個具體時間和葉柄顏色。 甄選
的雜交葉柄顏色(由1988年)、布爾代也有其限制,
,才是可靠的工作純黃色,紅色或綠色
葉柄的使用。 此外,許多品種雜交,是
點較少在初期階段作出不同形態甄選和評價工作更困難。 查明真正
D
T(侏儒
高)雜交的幼兒園階段仍更
困難的任務如果女家長是一個綠色箭在這種情況 下,
葉柄顏色不十分有用的雜交的甄選。 雖然普遍
通過和實行基於形態,純度評估是
往往受影響的環境,除了較高的要求,
時間和資源。 身份查驗的分子標記為區分
廠-類型字符,因此,必須以隔離
真正到類別高產高樓和混合路線的早期階段
的椰子繁殖方案,將有助於
商業混合幼苗生產活動的椰子。 區分
的侏儒,高樓和混合類型的托兒所的
合並應用的形態和分子標記預期將會確保高質量的種植材料在
遺傳 純度.
在 這項研究,我們描述一個技術的DNA匯集和
中技術,確定標記與泰勒-類別Palm特性
在椰子。 的方法,匯集DNA traitspecific
標記已被隔離,在早些時候報道中國棗樹(彭
et al同上,2001)、ponkan國語(錦屏et al,2009年)和茇 葡萄
(khadke et al,2012年),這種方法被証明是有效
和實際的椰子 太.
中 的忠誠,作為一個基因標記技術已被
質疑的,因為許多技術缺點聯系
與中的技術。 再生性的,是
中受影響的許多因素的質素的模板:DNA,集中
的底漆和模板,不同來源的DNA
การแปล กรุณารอสักครู่..
