小麥品種間雜種優勢與組合力之研究

English Summary Heterosis and Combining Ability on Six Spring Wheat Varieties

萬雄(Hsiung Wan) ； 王慶一(C.I. Wang) ； 呂宗佳(T.C. Lee)

《中華農業研究》 22卷2期 (1973/06) Pp. 161-171

https://doi.org/10.29951/JARC.197306.0001

摘要

（一）本試驗以六個小麥品種：臺中3號，臺中29號，F1orence. Sorona 64. Lerma Rojo 64及昭和早生進行全互交，研究這六個品種的雜交優勢和組合力，作爲育成雜種小麥的參考。
（二）供試六品種交配所得之15個雜種F1及6個親本品種進行試驗，採用逢機區組設計，單行區，行長1.5公尺，株距10公分，收穫中間10株作產量及農藝性狀的調查。1970年在臺北舉行，重雜6次；1971年在臺中舉行，重雜5次。
（三）1970年各性狀的平均成績，顯較1971年爲劣（表1），此乃由於1970年臺北氣候惡劣，環境遠較適於小麥生長之臺中地區爲差之故。
（四）F1雜種優勢的表現，就產量而言，1970年表現較高雜種優勢。15個F1中有3個顯較高親爲優，4個顯較兩親平均爲優，與高親比較之平均雜種優勢爲23.4%（表2a）。1971年則有4個雜種F1較兩親平均爲高，但役有較高親爲高者。較兩親平均的平均雜種優勢爲10.5%（表2b）。此一結果說明F1在不良環境下有較大的適應力。
株高則僅略優於兩親平均，大部F1都較高親爲低；每株分蘗數與每株穗數相關，故兩者結果相似，顯示F1優於兩親平均，但1970年也略多於高親，而1971年則否。穗長，每穗小穗數及每穗粒數三者的結果也相近，F1平均與兩親平均相似而較高親之穗長爲短，小穗數爲少，每穗的粒數也較少，1971年這三性狀並無雜種優勢表現。千粒重則兩年均顯示雜種優勢，F1平均較高親之麥粒爲重。
（五）組合力分析結果，一般組合力爲主要的變異來源，不論1970或1971，各性狀的一般組合力均極顯著，兩年產量的特定組合力均不顯著。其他性狀則1970年僅穗長，每穗粒數及千粒重顯著；1971年則有6個性狀顯著。依一般組合力效應而言，兩年的趨勢完全一致，其中Florence產量及各性狀均有正值效應，再就其F1產量的雜種優勢（圖1及圖2）的表現，可認爲是本試驗中最佳的雜交親本。不過這一品種的成熟期稍遲，由於本省耕作制度的限制，早熟爲必需的性狀。依據遲熟×早熟的F1的成熟期較早熟者略遲的結果，因此這一品種宜與較早熟品種雜交，雜種F1，才有可能應用。Sorona 64品種的產量雖不及Florence，但成熟期早，雜種優勢亦佳，故爲次佳的雜交親本。

並列摘要

The utilization of heterosis is interested by many breeders Since the discovery of cytoplasmic male sterility in wheat. However, the combining ability differs greatly among wheat varieties. Six wheat varieties, Taichung 3, Taichung 29. Florence, Lerma Rojo 64 'Sorona 64 and Showa-wase, used in developing cytoplamic male sterile lines and restoring lines were crossed in a diallel system to study the magnitude of heterosis and their combining ability in Taipei in 1970, and in Taichung in 1971.
Six parent varieties and their 15 F1 hybrids were studied in a randomized complete block experiment of 6 replications in 1970 and 5 replications in 1971. Each single row plot consisted of 15 individual plants of which only 10 plants were harvested and their characters measured. The rows were 40cm apart and the individual plants were spaced at 10cm. in the row. Eight agronomic Characters measured were yield per plot (gm), plant height (cm), no. of tillers per plant, no. of spike per plant, spike length (cm), no. of spikelet per spike, no. of kernel per spike and weight of 1000 kernels (gm). The data were recorded on plot basis and analyzed by using Griffing's Method Ⅳ, Model Ⅰ. (one set of Fi's).
The mean values of eight characters in 1970 were significantly lower than that in 1971 because of the weather difference in this two years and two locations (Table 1). Taichung was the area most adapted to wheat growing.
F1 heterosis was expressed as the percent increase over mid-parent and better parent. For grain yield, 3 of 15 hybrids were significantly better than the better parent and 4 were significantly better than the midparent(Table 2a), average heterosis over the higher parent was 23.4% in 1970; 4 of 15 hybrids were significantly better than the midparent, but no hybrid was significantly higher than the better parent, average heterosis over midparent was 10.5% (Table 2b). This results indicated that F1 hybrids were more adaptable than the parents under adverse condition.
Plant height of F1's was a little taller than the midparent, most of the hybrids were shorter than the higher parents. The results of No. of tillers per plant and No. of spike per plant were the same, that in 1970, the hybrids showed heterosis over higher parent; but only showed heterosis over midparent in 1971.
The manifestation of heterosis for length of spike, No. of spikelet per plant and No. of kernel per spike showed the same trend. Only average heterosis over midparent was found in 1970. There was virtually no heterosis expressed in 1971.
Heterosis over higher parent for weight of 1000 kernels was found in both years.
General combining ability was found to be the important Source of variability. They were significant for all characters studied. There were only 3 characters in 1970 and 6 in 1971 significant for specific combining ability, not including plot yield in both years. F1orence had the highest parental yield (Table 1) produced highest yielding F1's (Figs. 1& 2) and gave largest positive general combining ability effects in both years, it was the best variety that could in hybrid wheat program. Howtever, Florence is a late maturity variety which must be crossed with an early variety in order to make the hybrid to be fitted in the cropping system in Taiwan. Sorona 64, an early maturity Variety having low parental yield but producing large heterosis may also be a promising parent variety in producing hybrid.