[小寶]

Chapter 21 Inbreeding: Unmasked Defects

Geneticists usually consider mating within a family as closely as first cousins to be inbreeding, and anything more distant to be line breeding. The word line used to mean family in this instance has a somewhat different connotation from that used in pure lines. It is about equivalent to the word kin in the expression ‘kith and kin’. Kith means a community of families and kin those related by heredity within the kith.

In the broad sense of the word, inbreeding means mating within a family. In another sense it means the purification of the stock. If we mate brother with sister, parent with offspring, uncle with niece, first cousin with first cousin, we are inbreeding. Anything further removed than first cousins, we shall not consider inbreeding.

Taking the second meaning of the word─purification the stock─and appreciating the full meaning of it, we see that inbreeding is not simply what most of us have previously thought. Inbreeding is the great means at the breeder’s disposal for originating new breeds, strains and families, purifying old, and for concentrating genes.

We have already seen that brother and sister are more closely related than parent and offspring. In order to fully comprehend the idea which is at the basis of inbreeding, think of the genes and the fact that they are always in pairs. Is it not plain, then that what inbreeding does is tend to make the pairs of genes uniform?

Before we can answer intelligently the question, ‘Is inbreeding desirable?’ we must know the characteristics in the germ plasm. If a man who breeds pigeons has reason to believe that there are genes which make for defects, surly he would not want to double these genes and make the offspring pure for a defective trait. He had better keep his progeny impure so that there will be a chance for this progeny to give rise to both good and bad, and then he can select the good. But the man who has genuine improvement of the breed at heart will see the question from a different angle. Some classic examples of inbreeding shed much light on this question.

<待續>
QUOTE: THE BASIS OF BREEDING RACING PIGEONS BY LEON F. WHITNEY, D.V.M.

[小寶]

用語解釋：

• 遠親繁殖( Outbreeding)

指將一羽雄鴿與一羽沒有任何血統關係的母鴿配對(反之亦然)。目的是希望作出的下代能有一羽或更多羽能與父母一樣或是更好。

• 近親繁殖( Inbreeding)

指在同一鴿系中讓兩羽血緣更為相近的鴿子配對。說得白話一點，就是我們可以從這兩羽鴿子的血統表上，看到牠們的父母擁有共同的祖先，屬於近親，但又不是極近親。父母鴿所擁有的共同祖先越多，牠們作出的子女則越是近親。

• 鴿系育種( Line breeding)

是近親繁殖的另一形式，指將鴿子與牠的某一羽上代配對。一個鴿舍可以運用這種方式建立不同的鴿系。

• 雜交育種( Cross breeding)

指將兩種同一物種(Species)不同類屬(Breed)加以配對。即使是不同類，只要是可以配對繁殖，其下代也同樣會具有繁殖力。不過雜交對賽鴿育種而言並不是很好的做法，因為雜交會稀釋掉鴿子的歸巢和競翔能力。有許多鴿友明明採用"遠親繁殖"(沒有任何血統關係的賽鴿配對)方式育種，卻常常誤以為是"雜交"。

• 異種雜交( Species Crossing)

這個方法有其限制。將非洲的岩鴿和賽鴿交配，結果牠們的下代卻出現了不育的問題(這和馬與驢交配所生的騾子，是一種非常有用的動物卻通常不育的情況類似)。現代賽鴿是特別為了比賽，歷經幾百年的汰選和與種所得到的產物，如果把未經汰選過的野鴿的基因引進賽鴿體內，將會失去競翔特質。這種方式沒有任何優點，認真的鴿友是不會採用的。

以上內容引用自《贏家管理》Dr. Wim Peters

[3546tw]

寶哥!!!!
感恩喔!!!!
謝謝您的文章。

[小寶]

希望有善心人士翻譯一下.....

[g320]

章節21 同系繁殖: 揭露缺點

遺傳學者通常考慮交配不越出家庭當做接近當做表兄弟姐妹個到是同系繁殖,和任何事更遠的到是品系繁育. 字線過去常常想要家庭在此情況下有有些不同的內涵從那使用於純系. 它是大約相當於字有親屬關係的在表達 ‘親友’. 親戚知己意味社區的家庭和家屬那些的敘述附近遺傳不越出朋友.

在廣義的字,同系繁殖意味交配不越出家庭. 在另外的感受它意味淨化的樹幹. 假如我們伙伴兄弟和姐妹,父母和後代,伯父和姪女,表兄弟姐妹和表兄弟姐妹,我們是同系繁殖. 任何事更遠地移動比表兄弟姐妹,我們將不考慮同系繁殖.

佔領第2意義字─淨化樹幹─和賞識滿的意義的它,我們看那同系繁殖是不簡單地什麼最多的的我們以前嘗思. 同系繁殖是偉大的方法在飼者’s處置為了引起新的品種,緊張和家庭,純淨舊的,和為了集中基因.

我們已經已看弟妹是更密切相關的比父母和後代. 為了完全地理解想法即是在基礎的同系繁殖,想起基因而且他們是總是成雙成對的事實. 那不是無格式,然後那同系繁殖做是注意做什麼一對基因制服?

在前問題我們能回答聰明地, ‘同系繁殖是合意的?’ 我們必須知道特徵在胚漿. 假如一男子誰品種鴿子有理由到相信那個有基因哪個走向缺點, 粗暴他將會不想要雙重這些基因和做這子孫純粹的為了一有缺陷的特徵. 他最好還是保持他的後嗣不純淨的因此有一偶然為了這後嗣到引起兩者利弊, 而且他能選擇這好的. 但是有真正的改進的品種在內心的男人會看問題從不同的角落. 一些經典的例子的同系繁殖流下許多的停落於這問題.

<待續>
引用: 基礎的飼養賽鴿 以利昂F.惠特尼,D..M.

作者: 小寶

希望有善心人士翻譯一下.....

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[kkeileen]

好厲害 這ㄍ聯盟素質都好高 果然是高手中ㄉ高手

[water]

不好意思....
我對"遠親繁殖"和"雜交育種"......還是很不了解.......

作者: 小寶

用語解釋：

遠親繁殖( Outbreeding)


指將一羽雄鴿與一羽沒有任何血統關係的母鴿配對(反之亦然)。目的是希望作出的下代能有一羽或更多羽能與父母一樣或是更好。









近親繁殖( Inbreeding)


指在同一鴿系中讓兩羽血緣更為相近的鴿子配對。說得白話一點，就是我們可以從這兩羽鴿子的血統表上，看到牠們的父母擁有...